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Abstract One-dimensional formations of unidirectionally interconnected heterogeneous, multiple-input multiple-output (MIMO) linear time-invariant (LTI) systems are studied in terms of the spatial propagation of initial conditions, disturbances and reference inputs. The proposed mixed frequency-domain and complex state-space formulation of the string leads to the stability theory of switching and uncertain polytopic systems, and so the tools available there can be adopted for the analysis of interconnected systems. It is shown based on this analogy that in certain important cases string stability conditions for homogeneous and heterogeneous interconnected systems coincide. In addition to presenting general string (in)stability conditions, the necessity of introducing the notion of string performance is demonstrated. Special attention is devoted to interconnected rank one systems, i.e., systems whose transfer matrices are of rank one. The topic is motivated by car following problems for which the available analysis tools fail to provide appropriate heterogeneous string stability conditions. A cooperative adaptive cruise control (CACC) example is presented to illustrate the usefulness of the approach. [ABSTRACT FROM AUTHOR]

Condition monitoring (CM) has been considered as a promising technique to improve the reliability of insulated gate bipolar transistors (IGBTs). Among various condition parameters, switching time is a good health status indicator to detect IGBT failures. However, on-line monitoring of the IGBT high-speed switching time is still difficult in practice due to the requirement of the extremely high sampling rate for signal acquisition. To overcome the technical difficulty, this paper provides an innovative compressed sensing (CS) method to achieve equivalent sampling performance for high-speed IGBT switching time monitoring with a lower sampling rate. By utilizing the sparse characteristics of an IGBT switching signal, the sampling rate in the CS method could be far less than the traditional Nyquist sampling rate. To clarify the method, the CM mechanism using IGBT switching time is first analyzed. Then, three key points in the CS method are studied, i.e., the selection of sparsifying basis, the design of a measurement matrix, and the implementation of a reconstruction algorithm. Finally, experiments are carried out to investigate the performance of the CS method for on-line CM. Experimental results show that the IGBT turn-offtime at different temperatures can be accurately monitored with a highly compressed sampling rate, which validates the feasibility and effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

Abstract In this paper, we investigate the mean–variance portfolio selection problem in a continuous-time setting. We assume that the coefficients in the model are random and adapted to the filtration generated by a Markov chain. Instead of using the embedding approach which is widely adopted in the existing literature, we study the problem from the viewpoint of mean-field formulation and provide a distinctive and straightforward approach. By introducing and discussing a new system of mean-field backward stochastic differential equations driven by a Markov chain, we obtain both the optimal strategy and the efficient frontier in explicit forms. In particular, we revisit the Markovian regime-switching model in which the coefficients are deterministic functions of the Markov chain. [ABSTRACT FROM AUTHOR]

Abstract Thermally grown tungsten oxide (WOx) thin film on a tungsten electrode is studied as a potential memristor material. Due to the dislocation formation inside the film, the device could present stable memristive characteristics without electroforming process. In this research, the opportunity of applying the WOx memristor to the multi-level resistive switching behavior based multi-level memory or artificial synaptic device was presented. In particular, the flexibility of the device shows the possibility of a future flexible memory device. Interpreting the memristive characteristics, the resistance switching mechanism was discussed based on the valance change at the device structure interface. Based on the simple fabrication process and electroforming-less operation, the results present the possibility of applying WOx based memristors in current electronic devices at an early stage. This work reveals a useful proposal of WOx based memristors for emerging device applications. Highlights • Memristive characteristics studies of thermally grown tungsten oxide thin film. • Investigation of electroforming-less, multi-level resistive switching. • Flexible memristive characteristics of tungsten oxide thin film device. • Interpretation of interfacial valance change based resistive switching behavior. [ABSTRACT FROM AUTHOR]

Understanding and controlling surface charge-induced polarization switching have attracted interest of researchers extensively, and the rich physical interactions between ionic and atomic displacements play a significant role in polarization reversal. In this work, we investigated the mechanism of surface charge-induced polarization switching in PbZr0.2Ti0.8O3 and BiFeO3 thin films by phase-field simulations. We observed ferroelectric polarization reversal by applying positive/negative charge on the top of a thin film, because the double well of free energy becomes asymmetric by applying surface charge. It is found that the nucleation of switching always starts from the surface and gradually expands into the whole film. In BiFeO3 thin films, the formation of an anti-vortex domain provides topological protection for hindering surface charge-induced polarization switching. The present study, therefore, contributes to a better understanding of charge-induced polarization switching and provides guidance for the experimental design of reversible electronic devices by selecting the appropriate polarity region. [ABSTRACT FROM AUTHOR]

The analog switching behavior of resistive random access memory (RRAM) is crucial for its application in neuromorphic computing. This paper investigates the switching mechanism of RRAM under sub-nanosecond and nanosecond pulse programming, with selected device materials and structures, using the kinetic Monte Carlo simulation method. The microscopic distribution of oxygen vacancies is simulated in all three spatial dimensions and in the time dimension (four-dimensional). According to the simulation results, thermal effects are a critical factor affecting the switching behavior. The thermal effects inside the HfOx switching layer can be almost completely eliminated by using sub-nanosecond pulses with low voltage, finally leading to good analog behavior. When nanosecond pulses are applied, effective heat insulation is the key to realizing analog characteristics. In general, the switching process is proposed to involve three stages. Having the lowest energy consumption, the first stage shows the greatest potential for achieving analog behavior. The use of heat-isolating structures, like capping layers and side wall materials with lower thermal conductance, could be a solution to improve the analog behavior of RRAM at the first stage when down-scaling the device size. [ABSTRACT FROM AUTHOR]

Abstract This paper studies the problem of the cooperative output regulation for a class of nonlinear multi-agent systems described by T-S fuzzy models subject to the jointly connected switching topology. The considered switching topology permits the topology to be disconnected at any time interval which is weaker than the connected topology assumption. By using the parallel distributed compensation, the fuzzy internal reference model for each agent is constructed to estimate the exogenous signal, based on which, the distributed dynamic fuzzy output feedback controller is designed. The constructed fuzzy internal reference model is a switched nonlinear system where each subsystem may be unstable. An efficient condition is presented to ensure the solvability of the cooperative output regulation. An example of coupled pendula illustrates the validity of the result. [ABSTRACT FROM AUTHOR]

This paper investigates the various switching sequences on a generalized 60 ∘ distributed coordinate system-based space vector pulse width modulation (SVPWM) algorithm for multilevel inverters. The main focus of this work is to improve the inverter output voltage profile by taking advantage of the redundancy inverter switching states. With the help of SVPWM algorithm, the three nearest vectors have to find out the synthesis of the V ref location and then by applying the various optimum switching sequences, the inverter produces less harmonic content in the output voltage compared to the conventional switching sequence. All the switching sequence designs are developed with the help of minimum change detector (MCD) by using switching redundancies in order to reduce inverter switching loss. Simulation results to analyze various sequences on the general SVPWM algorithm are presented in the seven-level cascaded H-bridge (CHB) inverter. To validate the results, hardware results are presented on the seven-level CHB inverter. [ABSTRACT FROM AUTHOR]

The participation of the prefrontal cortex (PFC), hippocampus, and dorsal striatum in switching the learning task from cued to place learning were examined in C57BL/6 and DBA/2 mice, by assessing changed levels of phosphorylated CREB (pCREB). Mice of both strains first received cued training in a water maze for 4 days (4 trials per day), and were then assigned to one of four groups, one with no place training, and three with different durations of place training (2, 4, or 8 days). Both strains showed equal performance in cued training. After the switch to place training, C57BL/6 mice with 2 or 4 days of training performed significantly better than DBA/2 mice, but their superiority disappeared during the second half of an 8 days-place training period. The pCREB levels of these mice were measured 30 min after place training and compared with those of mice that received only cued training. Changes in pCREB levels of C57BL/6 mice were greater in the hippocampal CA3, hippocampal dentate gyrus, orbitofrontal and medial PFC than those of DBA/2 mice, when mice of both received the switched place training for 2 days. We further investigated the roles of orbitofrontal and medial PFC among these brain regions showing strain differences, by destroying each region using selective neurotoxins. C57BL/6 mice with orbitofrontal lesions were slower to acquire the place learning and continued to use the cued search acquired during the cued training phase. These findings indicate that mouse orbitofrontal cortex (OFC) pCREB is associated with behavioral flexibility such as the ability to switch a learning task. [ABSTRACT FROM AUTHOR]

Abstract This paper focuses on studying the distributed leader-following consensus problem of heterogeneous second-order time-varying nonlinear multi-agent systems (HSTN_MASs) under directed switching topology. Firstly, based on the relative position and relative velocity measurements among neighborhood agents, a class of distributed tracking protocols are proposed. Then the state transformations are provided to solve the time-varying nonlinearity and translate the leader-following problem into the stabilization control problem. By constructing the topology-dependent Lyapunov function and choosing appropriate time-varying regulation factor and coupling strength, it is shown that the exponential tracking of HSTN_MASs can be achieved. Moreover, this paper discusses the distributed leaderless consensus problem of HSTN_MASs. Finally, several simulation examples are given to illustrate the validity of theoretical results. [ABSTRACT FROM AUTHOR]

This paper studies the group consensus problem of second-order multi-agent systems (MASs) with switching communication topology. Unlike most existing papers concerning the consensus issue of MASs under arbitrary switching topology or Markovian switching topology, our paper tries to design a switching signal such that MAS can achieve group consensus under a designed switching signal set. First, using a state transformation method, the group consensus problem of MASs can be equivalently transformed into the asymptotical stability of a corresponding switched system. Then, two sufficient criteria are established by using Lyapunov function method and average dwell time (ADT) approach, where the minimum ADT τ a is given clearly. Finally, simulation examples are given to show the effectiveness of our theoretical analysis. [ABSTRACT FROM AUTHOR]

A temperature-switching irradiation (TSI) sequence has been developed that is based on a first-principles understanding of interface-trap buildup and annealing. The dynamics of interface-trap buildup and annealing during elevated temperature irradiation are described in detail to provide background, context, and enhanced understanding of the TSI method. The method is shown to be a practical and conservative test for enhanced low-dose-rate sensitivity (ELDRS) in linear bipolar devices and ICs. Examples of TSI sequences are shown for target doses up to 200 krad(Si), a range of great practical interest for space applications. The method can be adapted for higher dose applications via similar approaches. Devices that do not exhibit ELDRS respond similar to TSI and high-dose-rate irradiation. [ABSTRACT FROM AUTHOR]

This paper studies the optimal transmission switching (OTS) problem for power systems, where certain lines are fixed (uncontrollable) and the remaining ones are controllable via on/off switches. The goal is to identify a topology of the power grid that minimizes the cost of the system operation while satisfying the physical and operational constraints. Most of the existing methods for the problem are based on first converting the OTS into a mixed-integer linear program (MILP) or mixed-integer quadratic program (MIQP), and then iteratively solving a series of its convex relaxations. The performance of these methods depends heavily on the strength of the MILP or MIQP formulations. In this paper, it is shown that finding the strongest variable upper and lower bounds to be used in an MILP or MIQP formulation of the OTS based on the big- $M$ or McCormick inequalities is NP-hard. Furthermore, it is proven that unless $P=NP$ , there is no constant-factor approximation algorithm for constructing these variable bounds. Despite the inherent difficulty of obtaining the strongest bounds in general, a simple bound strengthening method is presented to strengthen the convex relaxation of the problem when there exists a connected spanning subnetwork of the system with fixed lines. With the proposed bound strengthening method, remarkable improvements in the runtime of the mixed-integer solvers and the optimality gaps of the solutions are achieved for medium- and large-scale real-world systems. [ABSTRACT FROM AUTHOR]

Inadequate frequency response can arise due to a high penetration of wind turbine generators (WTGs) and requires a frequency support function to be integrated in the WTG. The appropriate design for these controllers to ensure adequate response has not been investigated thoroughly. In this paper, a safety supervisory control (SSC) is proposed to synthesize the supportive modes in WTGs to guarantee performance. The concept, region of safety (ROS), is stated for safe switching synthesis. An optimization formula is proposed to calculate the largest ROS. By assuming a polynomial structure, the problem can be solved by a sum of squares program. A feasible result will generate a polynomial, the zero sublevel set of which represents the ROS and is employed as the safety supervisor. A decentralized communication architecture is proposed for small-scale systems. Moreover, a scheduling loop is suggested so that the supervisor updates its boundary with respect to the renewable penetration level to be robust with respect to variations in system inertia. The proposed controller is first verified on a single-machine three-phase nonlinear microgrid, and then implemented on the IEEE 39-bus system. Both results indicate that the proposed framework and control configuration can guarantee adequate response without excessive conservativeness. [ABSTRACT FROM AUTHOR]

Individual microgrids have proven their ability to provide uninterrupted power to critical end-use loads during severe events. Building on the performance of individual microgrids during extreme events, there has been an increasing interest in the operations of network microgrids. By networking microgrids during extreme events, it is possible to share resources, increase the duration for which they can operate islanded, improve efficiency, and increase the resiliency of critical end-use loads. While there are benefits to networking the operations of resiliency-based microgrids, the switching operations that they require introduce transients, which can result in a loss of dynamic stability. The issue of dynamic stability is especially acute in microgrids with high penetrations of inverter-connected generation, and correspondingly low system inertia. While the low inertia of these microgrids can be increased by over-sizing the rotating generators, the increased capital and operating costs can become a barrier to deployment. This paper will present a method of augmenting primary frequency controls to support the switching transients necessary for the operation of networked microgrids, without the need to over-size rotating machines. [ABSTRACT FROM AUTHOR]

Provides information on a study which examined the activation field, fatigue, and waiting-time effects in KNO[sub3] thin-film memories. Features of the films examined; Limitation in the data about the field dependence of switching times; Description of the primary effect of fatigue; Phenomenon important in designing ferroelectric memories.

Presents a study on the narrow time range where switching current displays a modest peak under an applied direct current field can be broadened to include the entire switching process. Forward and reverse change densities as functions of time for nonirradiated and irradiated films; Comparison between the theoretical and measured current densities for the nonirradiated film; Occurrence of growth of domains within the crystalline region.

Focuses on a study which demonstrated that bistable electro-optic effect can be obtained in a nematic liquid-crystal configuration having 270° twist and 30° boundary tilt. Analysis of the switching behavior; Transient transmission characteristics of bistable at various timescales; Results and discussion.

Provides information on a study that examined the open-circuit voltage-decay of a highly forward biased p-n junction diode switched off abruptly after reaching steady state at high-level injection. Methodology of the study; Results and discussion on the study.

The adiabatic switching method is used to calculate the semiclassical vibrational eigenvalues of H+3, D+3, and T+3. The results are in good agreement with quantum calculations and are more accurate than previous semiclassical results. The calculations were facilitated by the use of hyperspherical coordinates. [ABSTRACT FROM AUTHOR]

Formulates the basic theory of molecular switching with the use of the semiclassical theory for one potential unit. Existence of the complete reflection phenomena and bound states in the continuum; Time-independent coupled Schrodinger equations.

Studies the electrical switching properties of electrically conductive polymer composites at high current densities. General feature in conductor-filled polymer composite materials; Qualitative model for the switching phenomenon; Nonmechanical way of limiting high power short-circuit currents; Applications in the circuit protection industry.

Presents a study on time dependence of switching fields in magnetic recording media. Introduction to magnetic recording media technology; Importance of time-scale dependence in magnetic recording; Measurements and models; Results.

Presents a study which investigated the effects of ferroelectric switching on the dielectric and ferroelectric properites in lead zirconate titanate ceramics. Physical background; Experimental procedures; Experimental results; Discussion and modeling; Summary and conclusions.

Examines the switching characteristics of silicon and GaAs-based devices operating in the low- and high-field regimes. Characteristics of an ideal power switch; Applications of high-power switches; Steady-state analysis of silicon- and GaAs-based majority carrier devices; Advantage of photoconductive switches over optothyristors.

Discusses a technique for Q switching lasers by inducing reflectivity changes in a laser cavity that contains multilayer-coated mirrors. Illustration of the concept of the device being discussed; Reflectivity of multilayered mirrors; Mechanisms leading to reflectivity changes.

Presents information on a study which investigated the switching behavior of ferroelectric capacitors experiencing arbitrary time-dependent electric fields and arbitrary initial conditions. Methods; Results; Discussion.

Deals with a study which described a method to determine the switching field distribution of powder assemblies of magnetically hard materials with a random orientation of the easy axes. Methods; Results; Discussion.

Presents the results of a two-dimensional steady-state and transient simulation to examine the switching behavior of a self-aligned AlGaAs/gallium arsenide heterostructure bipolar transistor (HBT). Description of a two-dimensional model used in the study; Drift and diffusion equations appropriate for heterostructures; Description of the self-aligned HBT structure simulated.

Focuses on a study which calculated the angular dependence of a switching field of imperfect ferromagnetic particles with special reference to barium ferrite. Analysis of the one-dimensional model of an infinite material where the calculation is based; Comparison of results; Discussion on the shape anisotropy effect as well as the effects of inhomogenous reversals in ideal specimens.

Presents information on a study which investigated the electrical switching in two-terminal devices based on thin V[sub2]O[sub2] . 1.6H[sub2[O gel films. Lamellar structure of the films; Experimental details; Current voltage characteristics of the films; Results and discussion; Conclusions.

The problem of medium term production planning and control is compounded in many manufacturing concerns by the wide variety of products and by the presence of stochastic variables. This paper presents a simple heuristic approach to the problem by essentially combining a simple linear decision rule with a switching algorithm to give multi-product control operating within capacity limits. The approach is examined in depth by description of an industrial study and the results of the study suggest that the method requires little computing time, that it is conceptually simple and that it gives good results. It is suggested that the approach could he extremely useful in a wide variety of batch manufacturing environments. [ABSTRACT FROM AUTHOR]

For the containment control problem of autonomous surface vehicles with external disturbances, a novel non-singular fixed-time control scheme is developed, where the multi-ship system consists of real leaders and followers. In contrast with traditional containment cases studied in most of the existing literature, real leaders are required to track the desired trajectories, and the followers need to get into the convex hull spanned by the real leaders in a fixed time. The method for solving the fixed-time containment control problem is divided into the following steps: Firstly, a fixed-time disturbance observer is designed to estimate the external disturbance for the leaders and the followers, and the estimation result is used to compensate for the input of the control system; Second, combined with fixed-time stability theory and a switch function, a non-singular fixed-time trajectory tracking controller for leaders is designed, such that the position tracking error could be bounded within a fixed time; Third, to achieve formation efficiently, a non-singular fixed-time containment controller strategy incorporating with graph theory is proposed for coordinating followers, such that the fixed-time stability can be ensured. Finally, simulation examples are given to demonstrate the effectiveness of the proposed method. • This paper addresses the containment control problem of ASVs by two layers, namely, trajectory tracking and containment formation control. • A non-singular control law is proposed for each follower to accomplish the fixed-time tracking with by the fixed-time stability theory and a switch function. • Based on fixed-time stability theory, an observer is is constructed to estimate the external disturbance, which can be achieved in fixed time. [ABSTRACT FROM AUTHOR]

This paper reports the coexistence of unipolar and bipolar resistive switching (BRS) in an Ag/ZnO/Pt structure fabricated by sputtering deposition at room temperature. The structure shows reproducible and stable unipolar resistive switching after electroforming with high compliance current (Ic)=40 mA, regardless of the applied voltage polarity. With low Ic=5 mA at electroforming, BRS was also observed; this phenomenon depended on the voltage polarity. Both states were stable and reproducible over 100 cycles. The switching mode was changed with adjusting Ic but the transition was irreversible. Based on the results, switching mechanism based on filament theory is proposed to explain both resistive switching. [ABSTRACT FROM AUTHOR]

The bit patterned media use one single domain magnetic island to record a bit. It can effectively push the superparamagnetic limit to higher recording densities. In this paper, we present and investigate a composite patterned media structure comprising of soft layer enclosed magnetic islands to significantly improve the writing capability of conventional writer. Systematic micromagnetic simulation studies reveal that the proposed structure has a different domain wall propagation mechanism and has less stringent requirement on the exchange-coupling strength as compared to conventional composite structures. [ABSTRACT FROM AUTHOR]

The switching process of a submicron-scale ferromagnetic thin-film is numerically computed and analyzed by using spectral representation in terms of the eigenfunctions of the self-adjoint operator which relates the magnetization vector field with the micromagnetic effective field. It is shown that only few spectral modes are involved in the dynamics. The analysis suggests that such basis functions could be used to develop spectral methods using only a considerable low number of modes. The general procedure to determine the nonlinear equation governing the evolution of the mode amplitudes is outlined. [ABSTRACT FROM AUTHOR]

Lee et al. [J. Appl. Phys 101, 034105 (2007)] studied the Fréedericksz transition of a nematic bent-core mesogen in a planar cell. They claim that they have distinguished two different nematic phases in optical experiments, a uniaxial phase at a high temperature and a biaxial phase at a lower temperature. The commented paper contains several problematic passages and the substantial parts of the conclusions are invalid. Some experimental data appear to be inconsistent or incorrectly interpreted. We review the data and their interpretation, and analyze which conclusions are actually justified. [ABSTRACT FROM AUTHOR]

In this work we propose to study the reversible susceptibility tensor (including the transverse susceptibility components) of a synthetic antiferromagnetic (SAF) structure. This study is motivated by the fact that knowing the magnetic anisotropy of SAF structure is essential for the device functioning and the transverse susceptibility is known as one of the best methods to determine magnetic anisotropy and switching properties of magnetic systems. The starting point of this work is the magnetization’s equation of motion Landau-Lifshitz-Gilbert for the coupled two layers. By solving the inhomogeneous system of linear equations on the magnetization’s spherical coordinate deviations, the susceptibility tensor of the SAF structure is obtained. Simplified equations for the very low frequency case are given. By comparing the plots of the susceptibility versus the applied field with the regular hysteresis loops one concludes that susceptibility experiments are more appropriate for switching investigations of the SAF systems. [ABSTRACT FROM AUTHOR]

We have measured current-induced magnetization switching for MgO-based tunnel junctions with different current amplitudes and pulse durations at room temperature. The pulse widths ranged from 50 μs to 1 ms and the current ratios J/JC0 ranged from 0.4 to 0.97 (JC0 is the intrinsic critical current density). The results showed that the model of thermal assisted spin-transfer switching works well for the range of low to medium current ratio. However, for high current ratio, the switching probability did not fit the simple exponential function but grew with the current ratio linearly. The corresponding values of energy barrier as the current ratio approaches to unity indicated that thermal activation may still play an important role in magnetization switching. [ABSTRACT FROM AUTHOR]

This study proposes a power flow methodology focused on the need for reconfiguration analysis in modern distribution networks. The proposal is based on the extended fast decoupled Newton-Raphson method, which uses the information of the network switching equipment status (open or closed). To deal with eventual islanding during a reconfiguration procedure, a numerical observability technique used in state estimation analysis has been adapted for topological processing when network segments are disconnected from voltage references. A complex per unit normalisation technique is employed so that the power flow calculation by the fast decoupled approach is viable, even for networks having high R/X ratio lines. Simulation results considering two distribution feeders, one of large size, with different topological conditions are presented. The performance of the proposed methodology qualifies it as a relevant computational tool to support network reconfiguration studies involving emergent distribution systems. [ABSTRACT FROM AUTHOR]

A design strategy of reducing the molecular symmetry was used to obtain a series of picrate-based high-temperature phase transition compounds. Their dielectric switching behaviours accompanied by phase transitions can be attributed to the order–disorder transitions of the cations and the displacements of both cations and anions. [ABSTRACT FROM AUTHOR]

We introduce a novel model order reduction (MOR) method for large-scale linear switched systems (LSS) where the coefficient matrices are affected by a low-rank switching. The key idea is to replace the LSS by a nonswitched system with extended input and output vectors---called the envelope system---which is able to reproduce the dynamical behavior of the original LSS by applying a certain feedback law. The envelope system can be reduced using standard MOR schemes and then transformed back into an LSS. Furthermore, we present an upper bound for the output error of the reduced-order LSS and show how to preserve quadratic Lyapunov stability. The approach is tested by means of a numerical example demonstrating the efficacy of the presented method. [ABSTRACT FROM AUTHOR]

Abstract In this study, we fabricated ReRAM devices with the structure Ti/AlO x /Pt by applying solution-processed AlO x film as the switching layer. This enabled us to analyze the effect of the MWI power on the resistive switching performance of ReRAM. The AlO x resistive switching layer deposited by the solution-process was subjected to PDA treatment with microwave power ranging from 600 W to 3000 W, and the resistive switching performance was compared with as-dep and CTA-processed ReRAMs. All AlO x -based ReRAM devices exhibited bipolar resistive switching characteristics, and MWI-treated devices had larger memory windows than as-dep and CTA-treated devices. These solution-processed AlO x ReRAMs were found to exhibit Ohmic conduction in the low-voltage range of both the LRS and HRS. The high-voltage range of HRS shows the Poole-Frenkel conduction mechanism. In addition, compared with the as-dep device, the PDA-treated devices exhibited stable endurance characteristics and uniform resistance distribution in 1000 cycles of the switching operation, and showed reliable retention characteristics for 10,000 s at both room temperature and high temperature. XPS measurements were performed to analyze the relationship between the resistive switching performance and chemical nature of the AlO x switching layer by varying the microwave power and heat treatment method. Highlights • Resistive switching of resistive random access memory (ReRAM) devices was studied. • Microwave irradiation (MWI) power of ReRAM solution-treated AlO x switching layers. • Effect of MWI ranging from 600 W to 3000 W evaluated. • Memory characteristics improved as MWI power increased. • X-ray photoelectron spectroscopy showed that oxygen increased stoichiometrically. [ABSTRACT FROM AUTHOR]

The article discusses the research on the electric current driven-magnetization switching in bulk Rashba semiconductor. According to the author the bulk Rashba system will explore functional correlation of electric polarization, magnetization, and electric current. Topics discussed include the design of manganese-doped germanium semiconductor thin films, the hole carrier density enhancing Hall effect, and the electrical transport properties in thin films.

In this paper, a direct torque control (DTC) with a variable switching instant is proposed for a permanent magnet synchronous motor (PMSM) fed by a two-level voltage source inverter (2L-VSI). The variable switching instant allows the switching behavior to occur at any instant within one control interval instead of being fixed at the discrete sampling instant, which can result in more switching states within a control interval, rather than increasing the switching frequency. To realize the variable switching instant, the proposed approach overthrows the traditional structure of DTC. The binary logic signal in the switching table is replaced with the continuous evaluating function that can reflect the trend of change of torque and flux modulus generated by all available switching patterns with different switching instants. All evaluating functions can compose the switching instant table (SI-table) offline. Based on the SI-table, the optimization process is adopted to calculate the switching instant and allocate the switching sequence online, which can capture a quasi-optimal switching pattern to reduce both the torque and flux modulus ripples under a low switching frequency. Finally, the feasibility and effectiveness of the proposed approach are verified by both numerical simulations and experimental results. [ABSTRACT FROM AUTHOR]

The batch process is a batch-repeated production process, which shows a multiple modal switching within the batch. This makes it difficult to use a single-mode analysis method to achieve accurate modeling and fault diagnosis. Therefore, a novel two-step phase partition idea is proposed based on improved affinity propagation (AP) clustering and sub-phase similarity diminishing scan (PSDS) method. In order to capture the dynamic characteristics of the modes switching, the improved AP clustering is used for phase preliminary partition, in which an effective method that is more suitable for complex batch process is proposed to calculate the similarity. For sub-phases generated by the phase preliminary partition, the internal process of each sub-phase also varies obviously with the development of duration, so an innovative method PSDS is proposed to implement phase fine partition. Then each sub-phase scanned by the PSDS method is identified and divided into stable parts and transition parts, which further reflects the change trend within the sub-phase. For the outliers and misclassification points that may arise during the process of phase partition, the solutions are put forward, respectively. Thus, the partition results with different characteristics are modeled and monitored separately by using the method of principal component analysis (PCA). A practical application on batch process, aircraft steering engine platform fault diagnosis experiment, is given to conform the feasibility and performance of the proposed method. [ABSTRACT FROM AUTHOR]