Synchronous Vector Research Articles

Vector pulsating solitons and soliton molecules under higher-order effects in passively mode-locked fiber lasers

We numerically study the transport dynamics of vector solitons in ytterbium-doped fiber lasers based on a coupled Ginzburg-Landau equation with higher-order effects. By adjusting the small signal gain coefficient and intracavity birefringence, the number of soliton molecules can be manipulated, the transmission of synchronous and asynchronous vector solitons and the generation of chaotic pulse sequences can be realized. Synchronous vector solitons can be generated when the intracavity birefringence is relatively low, the stable transmission of multi-soliton molecules and the interaction between soliton molecules can be achieved. By changing the value of the phase delay, periodic pulsating solitons can be produced. Furthermore, the phenomenon of the pulse train from the period-doubling to chaos can also be observed. With the enhancement of the intracavity birefringence, asynchronous vector solitons can also achieve stable transmission in the cavity, which the amplitudes and widths of two components are opposite with the different phases. The proposed model has universal application value and the numerical results have guiding significance for studying polarization tunable lasers and exploring the nonlinear mechanism in fiber lasers.

Parameter identification of electric power remote telemetering system based on real-time section data and error-preventing topology analysis

Abstract In order to improve the security of power remote telemetry system, this paper studies the parameter identification method of power remote telemetry system based on real-time cross-section data and error-proof topology analysis. The method is based on a synchronization vector measurement unit. It uses the multi-source measurement method to fuse the real-time cross-section data of the power remote telemetry system, we reconstruct the fault-proof topology map of the power grid based on the fused real-time cross-section data. And according to the grid error prevention topology diagram, we set the grid line impedance parameters, calculate the sum and variance of voltage squares and so on. After the set parameters are established, the constraint conditions are divided, and the constraint conditions are transformed by linear function through quadratic programming. By judging whether the parameter identification function complies with its constraints, the parameter identification of the power remote telemetry system is realized. The experimental results show that this method can accurately obtain the real-time cross-section data of the power remote telemetry system. Moreover, it can accurately reconstruct the fault-proof topology of the power grid, and the maximum deviation of parameter identification is only 0.5223.

EVALUATION OF THE ERROR EFFECT IN SYNCHRONOUS VECTOR MEASUREMENTS OF ANGLES AT VOLTAGES ON ASSESSING THE DUTY PARAMETERS OF ELECTRIC POWER SYSTEMS

Telemeasurements and telesignals coming from telemechanics devices to the operational information complex are used as the initial data for solving the problem of state assessment. The disadvantage of telemeasurement chopping is that they do not contain angles at voltages that are necessary for assessing the mode parameters in solving a number of technological problems. Implementing the Transitional Modes Monitoring System has provided opportunities to improve solving the problem of state assessing by the data of synchronous vector measurements coming from synchronous vector measurement devices. However, failures on the satellite channel of synchronous vector measurement devices, as well as high load of communication networks result in errors in the arrays of synchronous vector measurements. The question of accuracy in solving the problem of state assessing at the influence of errors in synchronous vector measurements of angles at voltages on the mode parameters is not fully studied and is at the stage of research. State assessment is done using algorithms based on mathematical methods. The existing algorithms do not make it possible to take into account synchronized vector measurements of angles at voltages and require modification. The article presents a modified algorithm developed on the basis of the Gauss–Newton method, making it possible to use telemeasurements and synchronized vector measurements together, to evaluate the impact errors in synchronized vector measurements of angles at voltages on assessing the mode parameters, to determine allowable error intervals according to conditions of ensuring correct estimation mode parameters, to make the conclusion on advisability to use synchronized vector dimensions of angles in solving the problem of state assessing. The algorithm is tested using computational experiments when evaluating such mode parameters as active and reactive load power, voltage module, power flows. On the basis of studies, the error intervals of angles have been revealed, beyond which taking into account the angles at voltages will contribute to improving the accuracy of state estimation. The parameters of the mode that are the most sensory to the increase of errors in synchronized vector measurements of angles are determined.

Robust video encryption for H.264 compressed bitstream based on cross-coupled chaotic cipher

In order to realize the secure transmission of the H.264 compressed video bitstream, a detailed analysis of the structure for video bitstream is performed. The parameter set and frame header data related to video decoding are retained, and the slice data payload in the network abstraction layer unit is selected as the encryption object. The video format is compliant under the premise of real time and security. The novel cross-coupled chaotic system is designed as the key stream generation component, and the key stream is closely related to the plaintext through the synchronization vector mechanism. When part of the ciphertext stream is lost, the subsequent units can still be decrypted normally, which solves the problem of robustness encryption and decryption for video stream based on chaotic cipher. Detailed performance testing and security analysis data show that the proposed scheme has obvious advantages over existing research in terms of time overhead, compression ratio, anti-chosen-plaintext attack and robustness.

Early detection of sudden infant death syndrome: Systematic neonatal ECG, genetic study and familial cascade screening

Cardiac resynchronization therapy (CRT) is now generally delivered via quadripolar leads. Assessment of the effect of different vector programs from quadripolar leads on ventricular activation can be now done using non-invasive electrocardiographic mapping (ECM).In nineteen patients with quadripolar LV leads, activation maps were constructed. The total ventricular activation time (TVaT) and the time for the bulk of ventricular activation (VaT10–90) were calculated.CRT delivered via a quadripolar lead significantly reduced TVaT and VaT10–90 by a mean of 16 ms and 31 ms, respectively, compared to baseline. There was a marked reduction in ventricular activation between the most and least synchronous vectors: 28% difference in baseline TVaT and 37% difference in VaT10–90.Changes in the configuration of an LV quadripolar lead significantly affected ventricular activation timings in both ischaemic and non-ischaemic subjects. This suggests that programming of the optimal pacing vector may need to be individually tailored.

Left atrial volume and voltage in patients with atrial fibrillation assessed by PentaRay catheter

Cardiac resynchronization therapy (CRT) is now generally delivered via quadripolar leads. Assessment of the effect of different vector programs from quadripolar leads on ventricular activation can be now done using non-invasive electrocardiographic mapping (ECM).In nineteen patients with quadripolar LV leads, activation maps were constructed. The total ventricular activation time (TVaT) and the time for the bulk of ventricular activation (VaT10–90) were calculated.CRT delivered via a quadripolar lead significantly reduced TVaT and VaT10–90 by a mean of 16 ms and 31 ms, respectively, compared to baseline. There was a marked reduction in ventricular activation between the most and least synchronous vectors: 28% difference in baseline TVaT and 37% difference in VaT10–90.Changes in the configuration of an LV quadripolar lead significantly affected ventricular activation timings in both ischaemic and non-ischaemic subjects. This suggests that programming of the optimal pacing vector may need to be individually tailored.

Non-invasive electrophysiological assessment of the optimal configuration of quadripolar lead vectors on ventricular activation times

BackgroundCardiac resynchronization therapy (CRT) is now generally delivered via quadripolar leads. Assessment of the effect of different vector programs from quadripolar leads on ventricular activation can be now done using non-invasive electrocardiographic mapping (ECM). Material and methodsIn nineteen patients with quadripolar LV leads, activation maps were constructed. The total ventricular activation time (TVaT) and the time for the bulk of ventricular activation (VaT10–90) were calculated. ResultsCRT delivered via a quadripolar lead significantly reduced TVaT and VaT10–90 by a mean of 16 ms and 31 ms, respectively, compared to baseline. There was a marked reduction in ventricular activation between the most and least synchronous vectors: 28% difference in baseline TVaT and 37% difference in VaT10–90. ConclusionChanges in the configuration of an LV quadripolar lead significantly affected ventricular activation timings in both ischaemic and non-ischaemic subjects. This suggests that programming of the optimal pacing vector may need to be individually tailored.

Modified Synchronous Vector Control Design of Multilevel Inverters for AC Grid Applications

This article presents a modified synchronous vector control design of a five-level cascaded H-Bridge inverter for integration of distributed generation (DG) resources to the power grid. The presented control strategy explores the limitations in the conventional synchronous vector control algorithm of grid-connected converter (GCC). The dynamic reference point (DRP) approach is considered to improve the performance of GCC. Compared with conventional control algorithm, DRP based control algorithm exhibits several specific advantages, such as increased reliability of the grid-interfaced converter, more active and reactive power injection capacity of the converter, and reduced cost of the converter. The objectives of control technique of the DG interface system are also employed to enhance the standard of the power grid. The optimized space vector pulse-width modulation (OSVPWM) control technique is used for grid integration. The simulation and experimental results are presented in order to validate the proposed functionalities of the grid-interfaced DG system. The effectiveness of the proposed control scheme is validated with better utilization of DG system, faster dynamics with reduced total harmonic distortion, better power factor, compensated load reactive power, and fault withstanding capability.

Research on the Data Synchronization of Cloud Stroke based on JSON

Cloud stroke is the cloud platform according to the medical association theory and combing cloud computing technology, build for the hospital systems which are involved in the medical association to sharing and exchange medical information. However, at this stage, there are some problems in the data exchange of the cloud platform: Firstly, every hospital in the medical association needs to configure a front machine and the front machine needs to connect with the cloud platform database directly. So there is a hidden risk for the cloud stroke. Secondly, the data synchronization vector is Excel file, the data reading efficiency is not very well, and at the same time, the front machine memory consumption is relatively very large. This paper, improve the data interactive process of cloud stroke, so that the front machine unneeded to connect with the cloud platform database directly. Then, design data specification and synchronization process based on JSON for cloud stoke information synchronization to compress the expenses, improve the speed and analysis the security of data synchronization.

Suppression of Low-order Current Harmonics in AC Motor Drives via Multiple Reference Frames Based Control Algorithm

A novel control algorithm devoted to remove undesired low-order current harmonics in AC motor drives is presented in this article. The proposed control algorithm combines a suitable multiple reference frame synchronous harmonic estimator and multiple reference frame vector control implementation to suppress the undesired harmonics contained in the motor stator currents. This control technique can handle positive-, negative-, and zero-sequence sets, keeping a satisfying dynamic behavior. The control technique has been evaluated by numerical simulations and experimentally tested on a permanent magnet synchronous motor drive.

Emergency Control of Small Power Plants Based on Synchronized Vector Measurements

The purposes and tasks of emergency control in electrical supply grids with small power plants are analyzed. A method for controlling the dynamic stability of a synchronous generator based on synchronous vector measurements is introduced.

Software Components Behavioral Adaptation Based on LTS

Compatibility is the precondition to ensure the correct interaction among components in composition process, how to make the mismatch components coordinate correctly is a vital problem in component composition. This paper first modeled component behavior by LTS and expressed action mapping as synchronous vector then defined the sequential relationship among synchronous vectors as adaptation contract. Thirdly we analyzed the different mismatch situations and corresponding adaptation strategies. At last designed adaptation algorithm to produce adaptor specification automatically and ensured the mismatch components can correct interaction under the mediation of adaptor and verified the validity of proposed method through an application system.

Classification of Two Class Motor Imagery Tasks Using Hybrid GA-PSO Based K-Means Clustering.

Transferring the brain computer interface (BCI) from laboratory condition to meet the real world application needs BCI to be applied asynchronously without any time constraint. High level of dynamism in the electroencephalogram (EEG) signal reasons us to look toward evolutionary algorithm (EA). Motivated by these two facts, in this work a hybrid GA-PSO based K-means clustering technique has been used to distinguish two class motor imagery (MI) tasks. The proposed hybrid GA-PSO based K-means clustering is found to outperform genetic algorithm (GA) and particle swarm optimization (PSO) based K-means clustering techniques in terms of both accuracy and execution time. The lesser execution time of hybrid GA-PSO technique makes it suitable for real time BCI application. Time frequency representation (TFR) techniques have been used to extract the feature of the signal under investigation. TFRs based features are extracted and relying on the concept of event related synchronization (ERD) and desynchronization (ERD) feature vector is formed.

Use of cloud information technology for control, monitoring, and management of distribution power grids

The use of cloud information technologies for measurement, control, and management of distribution power grids with direct and alternating current couplings are considered. Requirements for databases for carrying out synchronous scalar direct-current measurements and synchronous vector alternating-current measurements are developed. Different scenarios of steady-state and transient regimes are examined. A generalized algorithm for the control and management of the distribution grid is proposed.

Validation of Novel Approach to Detect Type Mismatch Problem Using Component Based Development

Adaptation software component is a crucial problem in component-based software engineering (CBSE). Components that assembled or reused sometimes cannot perfectly fit one another because of the incompatibility issues between them. The focus today is on finding adaptation technique, to solve the mismatch between component interfaces and to guarantee that the software components are able to interact in the right way. This paper will focus on detecting mismatch, which considers as an important step through adaptation process. We propose a solution to detect mismatch, by suggesting improvement in Symbolic Transition Systems that used in representing component interface, and synchronous vector algorithm to deal with parameters data type mismatch.

Electromotive Triggering and Single Sweep Analysis of Vestibular Evoked Myogenic Potentials (VEMPs)

Cervical (c) and ocular (o) vestibular evoked myogenic potentials (VEMPs) provide important tools for measuring otolith function. However, two major drawbacks of this method are encountered in clinical practice. First, recording of oVEMPs is compromised by small n10 amplitudes. Second, VEMP analysis is currently based on the averaging technique, resulting in a loss of information compared to single sweep analysis. Here, we: 1) developed a novel electromotive trigger mechanism for evoking VEMPs by bone-conducted vibration to the forehead and 2) established maximum entropy extraction of complex wavelet transforms for calculation of phase synchronization between VEMP single sweeps. Both c- and oVEMPs were recorded for n=10 healthy individuals. The oVEMP n10 amplitude was consistently higher (right: 24.84±9.71 μV; left: 27.40±14.55 μV) than previously described. Stable VEMP signals were reached after a smaller number of head taps (oVEMPs 6; cVEMPs 11) compared to current recommendations. Phase synchronization vectors and phase shift values were successfully determined for simulated and clinically recorded VEMPs, providing information about the impact of noise and phase jitter on the VEMP signal. Thus, the proposed method constitutes an easy-to-use approach for the fast detection and analysis of VEMPs in clinical practice.

Presenting a new search strategy to select synchronization values for classifying bipolar mood disorders from schizophrenic patients

There is a growing interest to employ synchronization methods to reveal natural connections among the brain lobes by measuring co-activations among EEG channels. Regarding high number of EEG channels, lots of synchronization indexes are determined between two by two channels leading to construct a high dimensional feature vector for each time frame. The objective of this paper is to propose an effective feature selection method to find discriminative synchronization indexes in order to classify patients with schizophrenia from those with bipolar mood disorder (BMD). The state-of-art synchronization methods from various domains such as phase-locking value (PLV), robust synchronization (RS), and synchronization likelihood (SL), were implemented to provide a rich feature set in order to classify the two groups. To increase the classification accuracy, a capable feature selection scheme is proposed entitled greedy overall relevancy (GOR) to select discriminative synchronization indexes. The elicited synchronization vectors of 53 subjects imposed to support vector machine (SVM) classifier and the classification result with and without applying GOR, provided 92.45% and 88.68% accuracy, respectively. Across-group variance (AGV) is chosen as a rival method to GOR; the selected features by AGV entered to the classifier resulting in 91.34% accuracy. Using pair T-test exhibits the significant superiority of GOR to AGV such that P-value determined less than 0.05. To the best of authors' knowledge, this is the first attempt to utilize the selected synchronization indexes as informative features applying to a classifier for diagnosing the psychiatric patients.

MPI-based parallel synchronous vector evaluated particle swarm optimization for multi-objective design optimization of composite structures

This paper presents a decentralized/peer-to-peer architecture-based parallel version of the vector evaluated particle swarm optimization (VEPSO) algorithm for multi-objective design optimization of laminated composite plates using message passing interface (MPI). The design optimization of laminated composite plates being a combinatorially explosive constrained non-linear optimization problem (CNOP), with many design variables and a vast solution space, warrants the use of non-parametric and heuristic optimization algorithms like PSO. Optimization requires minimizing both the weight and cost of these composite plates, simultaneously, which renders the problem multi-objective. Hence VEPSO, a multi-objective variant of the PSO algorithm, is used. Despite the use of such a heuristic, the application problem, being computationally intensive, suffers from long execution times due to sequential computation. Hence, a parallel version of the PSO algorithm for the problem has been developed to run on several nodes of an IBM P720 cluster. The proposed parallel algorithm, using MPI's collective communication directives, establishes a peer-to-peer relationship between the constituent parallel processes, deviating from the more common master-slave approach, in achieving reduction of computation time by factor of up to 10. Finally we show the effectiveness of the proposed parallel algorithm by comparing it with a serial implementation of VEPSO and a parallel implementation of the vector evaluated genetic algorithm (VEGA) for the same design problem.

Research on Two-Stage Three-Phase Photovoltaic Grid-Connected System

Nowadays the penetration of PV-generated power energy into the utility grid is increasing exponentially. This paper focuses on two-stage three-phase grid-connected PV systems, which includes modeling of three-phase grid-connected PV systems, grid-connected control strategy of inverter. The inverter based on the grid-voltage oriented vector control used SVPWM-based synchronous current vector PI controllers to control the grid-current of the common point in three-phase grid-connected system. Theoretic analysis and experimental results on a 2.5KW prototype verify the presented algorithm.

Israeli Art Music: A Reintroduction

Israeli art music reveals that the soundtrack of Israeli history is greater than the sum of its parts, which usually include popular and folk music genres. Surveying the development of Israeli art music from the late 1930s to the 1970s, this article attempts to transcend the periodic partitions that characterize the field's historiography, which has had little contact with recent historical and historiographic shifts in the study of Israeli history. Focusing on four synchronous vectors—namely, processes of autoexoticism, asymmetrical musical borrowing, the post-statehood dilution of national sentiment, and the post-67 reemergence of Jewish musical idioms—the article guides the reader through the dissolution of national art music and its post-statehood stratifications.