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Hydrothermal vent fluids play very important role in the deep-sea geochemistry cycle, and support the extreme biological communities. But, there are very few sensors can be used for the in situ measurement of the chemical compositions of the emerging vent fluids. The extremely high temperature and pressure will kill most of them. The traditional sampling technology cannot maintain the sample temperate...
Full Feed-forward (FF) approach has been proved to be an effective method to suppress the output current distortion of the LCL type grid-connected inverter (GCI) due to grid voltage harmonics. Since most of the existing FF approachs are realized by digital control, a futher study of the digital control based (DCB) FF approach has been carried out in this paper firstly. It is shown that, there are...
In this paper, the stability study of a multiple offshore parallel long-cable-connected inverters (MOPLI) systemhs has been presented. It is shown that, since this MOPLI system is consisted of a large number of different inverters and long cables, its stability assessment actually faces big challengs. In addition, though there are lots of existing impedance-based stability criteria about prallel inverters,...
In this paper, we propose a backstepping based nonlinear control strategy to ensure the transient performances for the Modular Multilevel Converter (MMC), especially under the emergencies like changing load and operating mode. According to the backstepping control technique, the control input is derived from the Lyapunov stability theory and the established mathematical model. Meanwhile, it can be...
A sub-1 V and ultra-low power consumption voltage reference has been implemented in a standard 0.18μm CMOS process, without using resistors and special threshold voltage devices. A temperature coefficient (TC) of 37.8 ppm/°C in a temperature range of −40°C∼60°C is achieved. The supply voltage ranges from 1 V to 3 V, and the line sensitivity (LS) is 0.02%/V. When Vdd is minimum, the supply current...
Large displacement elastic joints have been widely used in rehabilitation exoskeleton, in this paper, a brief reminder of the application of large displacement elastic joints in exoskeleton robotic structures has been given. A new concept of rigid-compliant exoskeleton joint has been presented using four-bar compliant linkage for exoskeleton robot applications. The paper describes the method of designing...
To avoid large overvoltage when the current of the dc-link inductor is interrupted, overlap time is added to the drive signals in current source converters, which results in the extra harmonic in grid current. Waveforms of AC side current before and after added overlap time are achieved from analysis of the current commutation process. The expression of overlap current is given according to the pulse...
The stability of bus voltage is the main target of DC microgrid operation. DC microgrid including constant power load, distributed generations employed droop control, and resistive load is investigated. The constant power load can reduce system stability margin, and even cause bus voltage oscillating. The droop control can share the current among different distributed generations, but it can result...
For simultaneous localization and mapping(SLAM) of underwater robots, the extended Kalman filter algorithm has the problems of slow convergence rate, low accuracy and poor numerical stability, and square root cubature Kalman filter SLAM algorithm (SRCKF-SLAM) for mobile robots is designed according to cubature Kalman filter (CKF) principle. The cubature rule is utilized to calculate Gaussian weighted...
In order to research the scattering characteristics of moving targets, a simulation method applied with quasi-static theory is proposed. Firstly, the CAD model of target is established and then the all-space static RCS database for this target is set up by electromagnetics software. Secondly, the flight track is established so that the real-time posture change can be described. The attitude angles...
Collaborative development of large-scale aviation software products across organizational boundaries adds new challenges to existing software engineering processes. In this paper, we propose a novel, linked data approach for handling the diverse software artifacts by adapting features from social network sites. The linked data is introduced into software engineering domain, which connects software...
Recurrent Neural Networks (RNNs) are naturally applicable to sequential processing and have achieved outstanding performance in analyzing natural language. However, RNN-based sequence labeling methods may encounter some problems, such as word ambiguous and low-fidelity of word segmentation, in sentiment parsing of Chinese microblogging texts because it cannot well grasp local contextual information...
A self-adaptive differential evolution with dynamic selecting mutation strategy (DSMSDE) is proposed to improve the performance of differential evolution algorithm by three improvements. Mutation strategies are dynamically selected, and the successfully updated individuals are stored into the archive, which is beneficial for improving the convergence performance. A mechanism that is related to the...
Aiming at the shortcomings that the gravitational search algorithm (GSA) is easy to fall into the local optima, this paper proposes a simplified gravitational search algorithm (SGSA). This improved gravitational search algorithm has the characteristics of faster optimization process and better convergence accuracy for solving unconstrained optimization problems. In the search process, SGSA discards...
Operating reliability has great significance for equipment condition monitoring and health evaluation. In terms of equipment to be evaluated, reliability assessment is a personalized problem. Traditional reliability assessment method relies on the probability and mathematical statistics methods, and has limited practical significance when it is used for real-time monitoring of a specific equipment...
The inhibitory impacts of spikes on LFP theta rhythms(4–8Hz) are investigated around sporadic spikes(SSs) based on intracerebral EEG of 4 REM sleep patients with temporal lobe epilepsy(TLE) under the pre-surgical monitoring. Sequential interictal spikes in both genesis area and extended propagation pathway are collected, that, SSs genesis only in anterior hippocampus(aH)(possible propagation pathway...
Changes in electroencephalogram (EEG) signals under repetitive magnetic stimulation at the acupoint of Guangming (GB37) were analyzed using nonlinear dynamics complexity. C0 complexity is a statistical indicators which can quantify time dynamics of EEG signals. The study compared the C0 complexity under magnetic stimulation at GB37 with those at a mock point, as well as the C0 complexity under visual...
This paper proposes a new Distributed Deny of Service attack in Named Data Networking, and analyzes the Interest Flooding Attack in the case of conspiracy between the consumer and the content provider. After collusion with the content provider server, the attacker sends an Interest Flooding Attack request that can be satisfied, and the content provider server delays a large enough time to return the...
The last decades have witnessed the development of degradation modeling based remaining useful life (RUL) estimation, especially for Wiener process based degradation models. However, most researchers paid their attention to the drift coefficient representing the degradation rate, while much fewer eyes focus on the diffusion coefficient. The under consideration of diffusion process may cause bias in...
This work presents a nonlinear least-square iterative algorithm for calibrating gyroscopic drift error based on vibration test. According to the practical data analysis of the output acceleration of vibration table, the output acceleration errors are verified to be periodic harmonic errors with certain harmonic amplitudes in repetitively tests when the running frequency of vibration table is invariable...
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