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Indirect rotor field oriented control (IRFOC) plays an important role in the high performance induction machine drives. In the indirect rotor field oriented control — based induction machine adjustable speed control system, the rotor field angle is usually obtained by the rotor angular velocity and the slip angular velocity. The rotor angular velocity can be sensed by an encoder with sufficient accuracy...
In this paper, a broadband fourth-harmonic mixer based on gallium arsenide (GaAs) Schottky barrier diodes working at 80–100GHz is designed. This fourth-harmonic mixer is simulated and attains low conversion loss below 14dB in the whole band. The design process and simulation results are explained in detail.
A wide variety of lower limb exoskeletons have been applied in the fields of load-carrying augmentation, walking assistance, and rehabilitation training. The traditional exoskeleton based on fully actuated joints can provide powerful assistance for human motion, while it is bulky requiring a large energy consumption, which limits its application. The passive and quasi-passive exoskeletons are weak...
This paper investigates the missile attitude control problem. The model used in this paper is with respect to the Euler attitude angles and their derivatives which can be measured and computed easily. A robust practical finite-time control algorithm is proposed based on the terminal sliding mode approach. It is proved that all of the signals in the closed-loop system are bounded and the tracking error...
This paper presents a novel ultra-low power voltage reference operational from supply voltage down to less than 0.9V. In the proposed reference circuit, the PTAT voltage is generated by feeding the leakage current of a zero-Vgs NMOS transistor to two diode-connected NMOS transistors, both of which are in subthreshold region; while the CTAT voltage is created by using the body-diodes of another NMOS...
To improve the network invulnerability, most strategies are designed for optimizing the network capacity to prevent the cascade overload without considering the network robust under external attacks. To address this problem, based on the classical scale-free network model, this paper proposed a link-based network topology optimization algorithm referred as LNTO. The algorithm removed links among hub...
This paper studies a speed sensorless permanent magnet synchronous motor (PMSM) drive system based on the adaptive observer method, analyzes the problem of instability in the low-speed electric mode according to the observer linearization method. To solve this problem, the observer augmented with a signal injection technique is researched. The simulation results show that the method is effective to...
This paper introduces a fast closed-loop control strategy for a pulse width and amplitude modulation (PWAM) boost-converter-inverter system for HEV/EV motor drives. The PWAM boost-converter-inverter system, in which the dc-link voltage is controlled to have a 6ω fluctuation following the output peak voltage envelop, provides several advantages over the traditional PWM boost-converter-inverter system,...
Large-scale data centers form the infrastructure backbone for supporting cloud computing. The network interconnecting the servers in the data center plays a crucial role in the performance and dependability characteristics of the data centres. With the plethora of data center network (DCN) topologies that have been proposed in the literature, there is a sore need for a standardized method for evaluating...
With more electrical equipment adopted in helicopter, structure and management of helicopter power supply system becomes more and more complicated, so automatic fault processing function has been widely used in power supply system. As it needs long development cycle and high cost to design power supply system, this paper establishes digital models of voltage/frequency detection module, GCU, TRU, BTB,...
A novel serpentine waveguide slow wave structure (SWSWS) with caps and posts is proposed. The HFSS simulation results show that the interaction impedance is enhanced and the phase velocity is reduced over the normal SWSWS. The novel SWSWS is suitable for as the high-frequency structure of compact, linear beam devices.
Comparing with commonly used sine-wave pulse width modulation (SPWM) method, Space Vector Pulse Width Modulation (SVPWM) method has higher utilization rate of DC voltage and smaller output waveform distortion. This article introduced SVPWM control technology into inverter, built a model of three phase inverter based on PSCAD/EMTDC simulation platform and detailed the implementation of SVPWM modulation...
A new unequal-error-protected space-time block code (UEP-STBC) is designed in this paper for multimedia transmission systems deployed with multiple antennas. Traditionally, a space-time code is designed to support a single information stream aiming to achieve a point on the fundamental rate versus diversity tradeoff curve, while this proposed class of codes has the capability of transmitting different...
Routing problems based on cooperative transmission for multi-hop wireless Ad hoc network have been studied in this paper. Inspired by Multipoint Relay computation, a cooperative routing algorithm is proposed in Ad hoc network, which select cooperative neighbors for cooperative transmission by checking whether the links between the node and its neighbors are symmetric or not. The performances of the...
In this paper, the validity of the near-field equivalent method is studied to solve the problem of distortion in simulations. To analyze the validity, the condition of the principle of equivalence is reconsidered. The relationship between the principle of equivalence and the methods of near-field equivalence and far-field equivalence is studied, results show that the distance between the antenna and...
Recently MapReduce programming model is becoming popular for large scale data intensive distributed applications due to its efficiency, simplicity and ease of use. The Hadoop implementation of MapReduce is one of the most popular tools for many programmers due its ability to hide details of parallel programming from the users. However work on simulating the Hadoop environment is still in its infancy...
Inverse problems in nano-biomolecular circuits typically involve stochastic functional elements that admit non-linear relationships between different circuit variables. In this regard, a factor graph representation serves as an important visualization and analysis tool that can be used to compute inferences over an arbitrary large-scale biomolecular circuit. Solving the inverse problem using a factor...
The reliability for measure and control system of a space environment simulator is analyzed in the paper to build the models. The paper systematically summarizes the state of measure and control system. The system structure and principles are introduced. According to requirement of environmental test, working procedures of the system are divided into the particular assignments. On the basis of reliability...
Multiuser diversity can significantly improve wireless system performance by exploiting the feedback information that conveys the channel quality. In multiple input-multiple output and orthogonal frequency division multiplexing (MIMO-OFDM) systems, the per subcarrier on per antenna feedback induces a substantial amount of feedback overload and requires high computational complexity. This paper addresses...
This paper proposes a new face recognition approach by using Independent Component Analysis (ICA) and Ensemble Classifiers based on Support Vector Machine (SVM). Firstly, to improve the quality of the face images, a series of image pre-processing techniques are used. Then the ICA based on Kernel Principal Component Analysis (KPCA) and FastICA is employed to extract features. At last, appropriate classifiers...
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