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Conventional distributed control has achieved a great deal of success in multi-parallel cascaded H-bridge (CHB) power supplies. However, conventional distributed controllers can have a seriously imbalanced output power due to a mismatch of the hardware or control parameters and form an unstable circulating current path between the CHB converters, which can lead to a couple of problems. (1) The stability and tracking performance of the branch current can become degraded. (2) The current-sharing reactor can be easily saturated. To optimize all the branch currents of multiple parallel CHB power supplies, a master–slave carrier-based model predictive control method is proposed in this paper. This control strategy can achieve an optimized current tracking performance and effective circulating current suppression. In addition, through carriers, H-bridge interleaving and branch synchronization can be easily achieved, which fixes the switching frequency. Thus, the advantages of model predictive control and interleaving can be combined. Based on the generalized branch current predictive model derived in this paper, when more than two paralleled CHB converters have different output powers, an optimized branch current response can be achieved and circulating current can be eliminated. Simulation and experimental results verify the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

For a number of years, due to exponential increase in the demand for sustainable environment, suspicious activities have recently been identified as over-serious threats that are continually processing and growing. Identifying suspicious activities in the domain of cyber security is considered as a growing concern of research. To deal with suspicious threats, network requires traffic surveillance accompanied by beardown security policies. In order to handle data outflow, spoofing, disruption of service, energy exploiting, and insecure gateways range of attacks issues, the existing intrusion detection systems (IDSs) have observed to be less efficient as many of them are not able to detect anomalies with the change in the definition of the attack. To build a protected system against various cyber-attacks in computer networks, in this study, we introduce a multi-parallel adaptive evolutionary technique to utilize adaptation mechanism in the group of swarms for network intrusion detection. After that, simulated annealing is incorporated into multi-parallel adaptive grasshopper optimization technique to further improve the agent quality of individual after each iteration. It has revolutionized in the recent era for efficient threat detection with great performance in a certain time limit. The simulations are performed on three IDS datasets such as NSL-KDD, AWID-ATK-R, and NGIDS-DS. The proposed technique is compared with various existing techniques using different evaluation metrics. The comparative analysis demonstrates that the applicability of proposed technique concerning its merits outperforms the others algorithms. [ABSTRACT FROM AUTHOR]

Compared with traditional neural networks, extreme learning machine (ELM) shows outstanding performances on speed and computation. Aiming at the problems that ELM needs more hidden layer neurons and meaningful features of data sometimes are sacrificed in order to improve the training speed, a novelty network multi-parallel extreme learning machine with excitatory and inhibitory neurons (MEI-ELM) is proposed based on the idea of biological neurons. In MEI-ELM, (1) A parallel system is introduced to make it more compact and reduce the number of hidden layer neurons. (2) The property of excitatory and inhibitory of biological neuronal for data processing is introduced to improve its performance. Through applying MEI-ELM, ELM, Fast Learning Network (FLN) and Fast Learning Network with Parallel Layer Perceptrons (PLP-FLN) to 11 classical regression problems, it can be obtained that MEI-ELM performs much better than the other methods in generalization and stability. [ABSTRACT FROM AUTHOR]

Multi-parallel grid-connected voltage source inverters (VSIs) are widely applied in the fields of renewable energy, energy storage, harmonic suppression, etc. However, these inverters may cause harmonic stability problems due to the interactions among the grid-connected inverters through the grid impedance, which can seriously threaten system stability. The impedance-based stability criterion provides an effective tool for analyzing harmonic instability issues and can be divided into two types, namely, a ratio type and a sum type. Based on the existing studies of the sum-type criterion, this paper further proposes a new sum-type form based on the global admittance from the PCC to assess system stability through frequency-domain analysis. This global admittance-based stability criterion can be used not only to analyze system stability, but also to reveal the influence of each VSI unit on system stability with a lower computational burden and provide guidance for resonance suppression, especially in the case of a large number of grid-connected inverters and asymmetric inverter parameters. Finally, a MATLAB/Simulink model and 400 kVA/400 V experimental platform consisting of six grid-connected VSIs were established, and the corresponding results are presented to verify the effectiveness of the proposed method.

Abstract: A parallel chromatographic procedure for the purification of milligram amounts of plasmid DNA was developed. Initial studies showed that ion-exchange membrane capsules displayed high capacity for plasmid DNA. Interestingly, a weak anion exchanger (DEAE) proved to be superior to the strong quarternary ammonium group with respect to elution and regeneration properties and the 75cm2 Sartobind D membrane capsule (MA75D, Sartorius) was selected for further studies. A method for reducing endotoxin levels by using CTAB as a precipitant was optimised. By introducing this step into the protocol, endotoxin levels could be reduced approximately 100-fold to ≤5EU/mg plasmid. The parallel procedure was set up on a multi-channel peristaltic pump and evaluated with four different vectors (2.7–11.5kbp). Starting with 5–10g of E. coli cell paste (wet weight) generally saturated the membrane adsorber, resulting in plasmid DNA yields close to 10mg. [Copyright &y& Elsevier]

Multi-parallel grid-connected voltage source inverters (VSIs) are widely applied in the fields of renewable energy, energy storage, harmonic suppression, etc. However, these inverters may cause harmonic stability problems due to the interactions among the grid-connected inverters through the grid impedance, which can seriously threaten system stability. The impedance-based stability criterion provides an effective tool for analyzing harmonic instability issues and can be divided into two types, namely, a ratio type and a sum type. Based on the existing studies of the sum-type criterion, this paper further proposes a new sum-type form based on the global admittance from the PCC to assess system stability through frequency-domain analysis. This global admittance-based stability criterion can be used not only to analyze system stability, but also to reveal the influence of each VSI unit on system stability with a lower computational burden and provide guidance for resonance suppression, especially in the case of a large number of grid-connected inverters and asymmetric inverter parameters. Finally, a MATLAB/Simulink model and 400 kVA/400 V experimental platform consisting of six grid-connected VSIs were established, and the corresponding results are presented to verify the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]