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This paper proposes an electrode line fault supervision strategy based on the high-frequency voltage standing-wave ratio (VSWR). The paper analyzes the VSWR from theoretical side of its characteristics of the lossless transmission line to the numerical characteristics of the VSWR under different electrode line operation modes. On the basis of VSWR of the high-frequency signal, the electrode line fault...
To meet the requirements of ultra-high speed protection on UHV transmission lines, this paper proposes a fault phase selection based on wavelet analysis theory, which can detect the mutations' time and size of singular signal in fault signal. Firstly, this algorithm transforms the transient fault current into model fault current to eliminate the impact of the various phases' coupling. Then modulus...
This paper points out the problems of digital relay protection tester and the new requirements of relay protection testing in smart substation, combining the key technology of automation relay protection tester and takinG full advantage of the IEC 61850 standard, such as the unified protocol, the configurable model file, the specification of State Grid's “Six Reunification” as well. In this paper,...
A hardware and software system design for transmission line inspection basing on quadrotor unmanned aerial vehicle (UAV) is proposed in this paper. To enhance the inspection efficiency, real time data processing for transmission line detection and following are required. This paper proposes the design of hardware structure, software structure, as well as a Kalman filter. The real flight experiment...
It is certain that the individual learners should be different from each other in order for a committee machine to reach the better performance. However, differences alone among the individual learners are not enough for the committee machine to predict well on the unknown data. It would be essential for each individual learner to be able to decide whether to learn to be different or not to the other...
In this paper, we propose a method for generating guide data, and investigate its efficiency and efficacy for on-line learning with guide data. On-line learning in this research updates a learning model initialized by the decision boundary making algorithm proposed by us in our earlier study. The problem is that, if the guide data are not properly generated, on-line learning may require high computational...
We compare the performance of multilayer perceptrons (MLPs) obtained using back propagation (BP), decision boundary making (DBM) algorithm and extreme learning machine (ELM), and investigate better method for developing aware agents (A-agent) that are suitable for implementation in portable/wearable computing devices (P/WCD). The DBM has been proposed by us for inducing compact and high performance...
An electrical method for characterizing optical filters is proposed and demonstrated based on low-frequency detection, which enables magnitude frequency response measurement with hyperfine resolution up to 50 kHz and doubled measuring frequency range in the electrical domain.
The power converter for more electric engine in aircraft requires high power density, which makes SiC extremely attractive for this application. In this work, a 50 kW SiC high power density converter with the topology of three-phase two-level voltage source inverter is developed. Meanwhile, an accurate mathematical model for the power loss and efficiency calculation is proposed, which is based on...
In order to limit the scattering of electron at grain boundaries (GBs) which contributes to the resistivity, it is necessary to reduce the number of GBs by increasing the grain size of Cu films. The grain growth evolution in nanotwinned Cu (nt-Cu) films prepared by electrodeposition is investigated in this study. For the purpose of understanding the nt-Cu grain growth occur on (100)-oriented Cu, a...
Most existing compressed sensing (CS) based radar imaging methods are based on the assumption that the targets are sparse enough, while in practice the targets are often spatially extended, which would degrade their inversion performances severely. In fact, the concentrations of the corresponding strong scatterers always form certain regions in high-resolution radar. Therefore, there still exist dependence...
A novel terahertz double-layered dielectric reflectarray antenna is proposed. A ground and two dielectric blocks constitute the array element. The phase tuning can be obtained by adjusting the dimensions of the blocks. The proposed reflectarray of 20×20 elements operates at 100GHz. The HFSS simulation results show that the maximum gain is 25.4dBi with the direction of 25° and the 1-dB gain bandwidth...
Document image quality assessment (DIQA) aims to predict the visual quality of degraded document images. Although the definition of “visual quality” can change based on the specific applications, in this paper, we use OCR accuracy as a metric for quality and develop a novel no-reference DIQA method based on high order image statistics for OCR accuracy prediction. The proposed method consists of three...
Almost all present successful general purpose blind image quality assessment (BIQA) models are designed only towards singly and synthetically distorted images. However, real world images generally contain multiply types of distortions other than single type of distortion. Even some state of the art BIQA methods cannot work well on authentically distorted images. In this paper we propose a novel effective...
A self-calibrated method based on the frequency-shifted heterodyne scheme is proposed and demonstrated for independent frequency response measurement of high-speed Mach-Zehnder modulators (MZMs), phase modulators (PMs) and photodetectors (PDs) with the same setup.
40-Gb/s all-optical wavelength multicasting is demonstrated employing a compact InP-based chip consisting of semiconductor optical amplifiers, an arrayed-waveguide grating and delay interferometers. 2.5dB and 3.2dB power penalties for NRZ and RZ signals were achieved, respectively.
Episodic memory dysfunction is one of the hallmark symptoms of Alzheimer's disease (AD) and mild cognitive impairment (MCI). This cognitive impairment may be related to abnormal brain structure and activity. Functional connectivity mapping (FCM) analysis provides a powerful tool for exploring the topology of human brain function using magnetic resonance imaging (MRI). Thus, it would be advantageous...
Negative correlation learning is an ensemble learning approach that is able to create negatively correlated learners simultaneously and cooperatively in a committee machine. One problem in negative correlation learning is that the learning error functions are defined in the same way for all individual learners. Learners have little choice in making their own decisions on how to learn a given data...
In this paper, 3-D finite element (FE) models were established to investigate the fatigue lives of bonding wire in different power packages in thermal cycling test. Meanwhile, three types of packages were tested. Bonding wire lift-off and neck failures took place during test, which were caused by the coefficient of thermal expansion (CTE) mismatch between wire and chip. Finally, a strain-based life...
This paper studies the traditional thin and large die pick up process by finite element simulation. A complicated transient dynamic model is developed to simulate the die pick up process by ANSYS/LS-DYNA. Multiple 3D contact pairs are set up between collet and die, die and tape, tape and die holder, tape and eject pins in simulation. The modeling of the adhesive de-bonding process is critical to the...
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