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In the literature, a number of methods have been proposed for semi-supervised learning. Recently, graph-based methods of semi-supervised learning have become popular because of their capability of handling large amounts of unlabeled data. However, the existing graph based semi-supervised learning algorithms do not optimize the process of selecting better labeled data. We have developed a new selective...
Currently, open source projects receive various kinds of issues daily, because of the extreme openness of Issue Tracking System (ITS) in GitHub. ITS is a labor-intensive and time-consuming task of issue categorization for project managers. However, a contributor is only required a short textual abstract to report an issue in GitHub. Thus, most traditional classification approaches based on detailed...
Enclosure circulation of Gas Insulated Switchgear (GIS) and Very Fast Transient Overvoltage (VFTO) are harmful to many respects of power system, including system's security, stability and economic. The effective inhibition of GIS enclosure circulation and VFTO has attracted wide attention. In this paper, GIS enclosure circulation and transient ground potential has been modeled and analyzed. Firstly,...
Since the capacitor equivalent series resistance (ESR) above 1kHz almost stays constant, dc-link current root-mean-square (RMS) closed form equation is an easy way to evaluate the capacitor losses from the switching harmonic currents (SHCs). But when the ac current contains multiple low order harmonics (LOHs), their impacts on the dc-link has not been systematically studied. In this paper, a straightforward...
Hybrid excited flux-switching machine (HEFS) is a novel brushless synchronous motor. Compared to conventional permanent magnet synchronous machine (PMSM) and permanent magnet flux switching (PMFS) machine, it has additional excitation winding in its stator to modulate the air-gap magnet field. In this paper, the topology and operating principle of HEFS is analyzed. Its dynamic mathematical models...
With the distributed generation (DG) infiltrated distribution network gradually, determining the allowable capacity of DG quickly under different distribution network is the key to design and safe operation. According to the steady-state voltage, current and short circuit current of the feeder with DG, a practical analysis algorithm of DG allowable capacity for radial grid and single ring grid is...
This article proposes a new approach to accomplish the mission of orbital transfer using the two finite variable thrusts. This problem requires attaining the two optimal time histories of the acceleration in the each thrust arc, which can be expressed as a polynomial function of time, and taking the corresponding coefficients as potential solutions can be obtained by using the particle swarm optimization...
To manage the microgrid effectively, it is important to get the power information among multiple distributed generation (DG) units. However, when the droop control method is adopted, as the corresponding DG units cannot be simply modeled as VF or PQ buses, the conventional power flow algorithm may become inapplicable. To solve this issue, a time domain iteration (TDI) based power flow algorithm is...
The construction of knowledge graph of dangerous goods (KGDG) is with great significance of inferring relative information of dangerous goods, developing corresponding policy for its storage and transport, preventing disaster caused by dangerous goods(DG), and providing emergency plan when the disaster happens. Since distributed representation of natural language is an effective method for knowledge...
Series arc fault is an important incentive for electrical fires. Wavelet transform is a widely used series arc fault identification method. However, it is difficult to distinguish the normal condition and arc fault when only using wavelet transform, and a large amount of redundant data will be generated. To solve this problem, this paper presents a new series arc fault identification method which...
A power electronics transformer (PET) based on dual active bridge (DAB) with input series and output parallel (ISOP) cascaded topology is studied in this paper. Fe-based nanocrystalline alloys transformer cores and Silicon Carbide (SiC) power MOSFETs are adopted to improve the power density and efficiency. Mathematical derivation of the input voltage distribution is deduced with the conclusion that...
For an islanded microgrid, load power should be properly shared among multiple distributed generation (DG) units, not only for the fundamental power but also for the harmonic power. In this paper, the operation of microgrids under imbalanced and nonlinear load conditions is studied, and a dynamic consensus based power controller is proposed for DG units to realize enhanced power sharing performance...
This article addresses the inverse kinematic problem of the general 6R serial robot via unit dual quaternion and Dixon resultant. Firstly, we show quaternion and dual-quaternion. Secondly, by the quaternion and dual quaternion theory, unit dual quaternion kinematics equations of 6R robots are derived. Thirdly, the solution process was constructed via elimination method and Dixon resultant; According...
Bipolar dc-dc converters, which are widely used in the battery testing equipment, have many advantages such as simple structure, wide range of output voltages and high conversion efficiency. However, the traditional synchronous carrier modulation method leads to a circulating current in the ground wire connected between filtering capacitors and the negative dc input bus. The circulating current results...
This paper proposes improved multi-loop control strategies for three-phase four-leg virtual synchronous generator with unbalanced loads. Through the decoupling control of active and reactive power, inverter can simulate the characteristics of synchronous generator, including primary frequency modulation, primary voltage modulation, inertia and excitation characteristics. To improve the dynamic performance...
Sintered silver has received a great deal of recent attention as a high-temperature die-attach material. A detailed study of the sintered silver for bonding insulated gate bipolar transistor dies is reported. The purpose was to compare the reliability between sintered silver and Sn-3Ag-0.5Cu (SAC305) solder joints. It was found that the sintered silver had a porous and crack-free structure. And compared...
We report the effects of multiple reflow cycles on the reliability of Sn-Sb solders. Reflow soldering technology was used to prepare the Sn-Sb joints after 1 reflow cycle, 2 reflow cycles and 3 reflow cycles. We found that the intermetallic compound layers became thicker and denser with the reflow cycle increased. And the samples here had good bonding quality with only a few voids. After 600 thermal...
On a PCB, the high-speed link layout design with high component density has to satisfy strict mechanical and electrical specifications. Not only does the design and manufacturing process become difficult, but also the correlation between measurements and simulations is extremely challenging. In this paper, we focus on the above-mentioned challenge encountered in the measurement correlation process...
We presented a 32-channel silicon hybrid demultiplexer fabricated with CMOS technology. Double-etched mode converter and wide arrayed waveguide are used to improve AWG performances while the counter-tapered coupler is optimized for broadband mode multiplexing.
In this paper, a very fast capacitor assignment algorithm capable of finding an optimized decoupling solution scheme that meets a predefined target impedance for a given power distribution network (PDN) is presented. The algorithm provides an optimal combination of decap values and decap locations while minimizing the number of decoupling components needed to meet RL-type target impedances. The algorithm...
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