Carbon nanotube (CNT) bulbs made of decimeter-scale double-walled carbon nanotube (DWCNT) strands and films were fabricated and their luminescence properties, including the lighting efficiency, voltage-current relatio...
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Carbon nanotube (CNT) bulbs made of decimeter-scale double-walled carbon nanotube (DWCNT) strands and films were fabricated and their luminescence properties, including the lighting efficiency, voltage-current relation and thermal stability were investigated. The results show that the DWCNT bulb has a comparable spectrum of visible light with tungsten bulb and its average efficiency is 40% higher than that of a tungsten filament at the same temperature (1400―2300 K). The nanotube filaments show both resistance and thermal stability over a large temperature region. No obvious damage was found for a nanotube bulb illuminating at 2300 K for more than 24 hours in vacuum.
This paper presents a novel approach to solve the constrained unit commitment problem using the Selective Self-Adaptive Ant Colony Optimization (SSACO) for improving search performance by automatically adapting ant po...
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ISBN:
(纸本)9789810594237
This paper presents a novel approach to solve the constrained unit commitment problem using the Selective Self-Adaptive Ant Colony Optimization (SSACO) for improving search performance by automatically adapting ant populations and their transition probability parameters, which cooperates with the Candidate Path Management Module (CPMM) and the Effective Repairing Heuristic Module (ERHM) in reducing search space and recovering a feasible optimality region so that a high quality solution can be acquired in a very early iterative. A new concept of the Relativity Pheromone Updating (RPU) is also introduced to provide a reasonable evaluation of the pheromone trail intensity among the agents. The proposed SSACO method not only enhances the convergence of search process, but also provides a suitable number of the population sharing which conducts a good guidance for trading-off between the importance of the visibility and the pheromone trail intensity. The proposed method has been performed on a test system up to 100 generating units with a scheduling time horizon of 24 hours. The numerical results show the most economical saving in the total operating cost when compared to the previous literature results. Moreover, the proposed SSACO topology can remarkably speed up the computational time of ant colony optimization, which is favorable for a large-scale UC problem implementation.
This paper presents an improved switching strategy for three-phase full-bridge converters applied to switched reluctance motor (SRM) drives. The modified switching strategy is based on the idea that in every electrica...
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ISBN:
(纸本)9788986510089
This paper presents an improved switching strategy for three-phase full-bridge converters applied to switched reluctance motor (SRM) drives. The modified switching strategy is based on the idea that in every electrical cycle the two switches in same leg of the converter alternate their commutating without using dead time. This drive method has several advantages including low cost, compactness, no dead time required, reduced number of switching pulses, and consequently reduced switching loss. The proposed method is analyzed and the experimental is investigated on 1.5 kW, three-phase 6/4 poles SRM which is designed for small electric vehicles by using standard three-phase full-bridge converter. The experimental results have confirmed an acceptable performance of this proposed technique.
This study presents an algorithm for multi-channel electroencephalographic (EEG) spike prescreening based on radial basis function (RBF) artificial neural network. Sixteen-channel EEG records from twenty-eight patient...
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This study presents an algorithm for multi-channel electroencephalographic (EEG) spike prescreening based on radial basis function (RBF) artificial neural network. Sixteen-channel EEG records from twenty-eight patients with epilepsy were examined online. The single-channel recognition network consisted of input-layer neurons receiving three EEG waveform parameters (peak angle, amplitude, and velocity), ten hidden-layer neurons, and one output neuron. An optimal network model was chosen according to receiver operating characteristics analysis. Identification of multi-channel geometric correlation was performed with an incidence matrix. Sensitivity and selectivity cross-over value was found to be 80% for the single-channel RBF network. Compared with error back-propagation, a substantial improvement in training efficiency by at least two to three orders of magnitude was obtained for the RBF network. Validation with visual analysis showed 87.3% sensitivity using the proposed online multi-channel classification algorithm. The computation time required for spike detection was significantly less than that needed for online display of the EEG record. The proposed algorithm was able to achieve classification accuracy similar to previous artificial neural network schemes based on error back-propagation, while the training needed for RBF network was substantially less. Therefore, the RBF neural network is potentially an effective tool in real-time prescreening for epileptic spikes.
We present a control strategy that combines local state feedback laws and open-loop schedules to robustly globally asymptotically stabilize a compact subset (typically a point) of the state space for a nonlinear syste...
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We present a control strategy that combines local state feedback laws and open-loop schedules to robustly globally asymptotically stabilize a compact subset (typically a point) of the state space for a nonlinear system. The control algorithm is illustrated on the problem of global stabilization of the upright position of the pendubot and implemented in a hybrid controller containing logic variables and logic rules with hysteresis. We also present the design procedure of the hybrid controller for general nonlinear systems. Recent results in the literature on robustness of asymptotic stability in hybrid systems are used in establishing that the closed-loop system is robust to measurement noise and other external disturbances.
This paper focuses on the asymptotic stability properties of omega limit sets for complex hybrid dynamical systems, which are commonly found in systems and engineering. It spells out specific stability results that fo...
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ISBN:
(纸本)7900719229
This paper focuses on the asymptotic stability properties of omega limit sets for complex hybrid dynamical systems, which are commonly found in systems and engineering. It spells out specific stability results that follow when a hybrid dynamical system has certain structure, e.g., when it admits a decomposition resembling a cascade of hybrid dynamical systems.
Modeling issues for hybrid dynamical systems are discussed and fundamental stability analysis tools are summarized. These tools are useful for the development of hybrid control algorithms.
ISBN:
(纸本)7900719229
Modeling issues for hybrid dynamical systems are discussed and fundamental stability analysis tools are summarized. These tools are useful for the development of hybrid control algorithms.
作者：
Prieur, ChristopheTeel, Andrew R.LAAS-CNRS
7 Avenue du Colonel Roche 31077 Toulouse Cedex 4 France Center for Control
Dynamical Systems and Computation Department of Electrical and Computer Engineering University of California Santa Barbara CA 93106-9560 United States
We consider control systems for which we know two stabilizing output feedback controllers. One is globally asymptotically stabilizing, while the other one is only locally asymptotically stabilizing. We look for a comp...
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In this paper, a design of the 3-phase, 6-stator-pole and 4-rotor-pole, 15 kW switched reluctance motor for the propulsion system of the electric vehicle is presented. Its performance such as the torque per volume and...
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ISBN:
(纸本)8986510081
In this paper, a design of the 3-phase, 6-stator-pole and 4-rotor-pole, 15 kW switched reluctance motor for the propulsion system of the electric vehicle is presented. Its performance such as the torque per volume and its efficiency are compared to the machine which is designed based on the conventional design guideline.
In this paper a method to estimate the initial rotor position of the switched reluctance motor (SRM) at the stand still condition is proposed. The proposed method can be implemented by the simple microcontroller based...
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ISBN:
(纸本)8986510081
In this paper a method to estimate the initial rotor position of the switched reluctance motor (SRM) at the stand still condition is proposed. The proposed method can be implemented by the simple microcontroller based system, and it is not necessary to know the magnetization curves. The impulse gate drive signal is applied and the winding current is detected and its approximate value is used for calculating the rotor position. The compensation method to reduce the estimation error thorough one cycle is also mentioned. The proposed method is implemented with the 6-stator-pole and 4-rotor-pole, 1.5 kW 3-phase switched reluctance motor.
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