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This paper presents a tracker using binocular camera capable of tracking a specific human in both indoor and outdoor environments. Based on the kernelized correlation filter (KCF), the proposed tracker detects the target in multiple scales with the integration of HoG, color naming (CN), and local depth patterns (LDP) features, which improve the tracking performance. Specifically, a precise positioning...
The reverse recovery characteristics of the high power thyristor becomes increasing important to the converter valve designers as commutation failure often occurs in its reverse recovery process. Therefore, the recovery protection of converter valve is provided by thyristor control unit. The design of thyristor control unit is associated with the relationship between reverse recovery characteristics...
The converter valve is the core equipment in the HVDC transmission power system and the thyristor level is the basic unit of HVDC converter valve, its performance has a direct effect on the reliability, stability and efficiency of the whole power system. Thus, each thyristor level in the converter valve needs to be test routinely during the maintenance period of the electric equipment in order to...
Compressive sensing theory can recover the original signal from little observation data, by means of the non-adaptive measurement far below Nyquist sampling and the optimization method. Due to the number of track is limited and the uneven distribution of tracks, the traditional method is difficult to image effectively in the practical application, while the compressive sensing theory by tomoSAR three-dimensional...
The high power thyristor is the basic unit in HVDC converter valve, and its transient performance has a tremendous influence on the reliability, stability of the whole power system and designs of thyristor control unit. For this reason, each thyristor needs to be tested routinely before the operation of the power system. However, there is no specification for the routine test of thyristor valve. The...
The design and performance of X-band (8-12 GHz) 6-bit MMIC phase shifter is presented. The phase shifter is fabricated in 0.25um GaAs pHEMT technology. Each bit of this phase shifter design is based on an optimum topology to reach balanced and optimal insertion loss, phase shifting accuracy and return loss. A new type of loaded-line topology for small phase shift states is also relevant. The adoption...
We have performed constant voltage stress (CVS) tests on GaN-on-SiC HEMT to investigate the drain current drift. Two kinds of current drift behavior are observed in CVS. The off-state drain voltage step stress tests are carried out to confirm the electric field dependent current drift. A critical voltage for drain current recovery is observed. We suggest that the recovery of drain current is due to...
Voltage step-stress tests on GaN-on-SiC HEMT showed that electric field is a driving factor for degradation. The position of localized damage is corresponding to the high electric field region. A degradation mode different from previous reports is observed, which led to an increase of drain current after stress in certain conditions. We attribute this to the collection of the positive mobile charge...
Database as a Service (DaaS) is a common service mode in Cloud Computing. Based on Feldman (t,n) VSS protocol and ElGamal homomorphism property, we proposed a privacy-preserving access control protocol for DaaS. Using Secret Sharing, we can protect the security of data owner's dataset, based on ElGamal homomorphism property, the data requester's query combining with the proxy servers' access control...
This article elaborates the concept and meaning of virtual reality technology and virtual maintenance, discusses the virtual reality technology application in the process of equipment maintenance, and gives a brief introduction to virtual maintenance system, which use VC and vega software as a platform and set up by Multigen Creator and 3D MAX, quoted an cannon as an example.
We have stressed GaN High Electron Mobility Transistors (HEMTs) with AlGaN back barrier on SiC substrate at high voltages at normal and high temperatures. A pattern of device degradation differs from what occurred in reported GaN-on-SiC HEMTs and GaN-on-Si HEMTs. The recoverable degradation of drain current is observed under Vds=0 step stress condition, but no degradation is observed under off-state...
Thermal performance of AlGaN/GaN HEMT is a critical issue during the design stage, since it significantly affect the lifetime of the device. This paper introduces a three-dimensional modeling technique including electro-thermal coupling effects for investing the thermal characteristic of the AlGaN/GaN HEMT. The method achieves a good balance between simulation time and accuracy through iterative calculation...
According to the geometric imaging characteristics of airborne Synthetic Aperture Radar (SAR) system, the methods of extracting three dimension information for some typical ground objects with height have been described in this paper, including image preprocessing, height information extracting of buildings and trees, the final visualization and so on. And, the test result provided a practical reference...
During the mapping task using high-resolution airborne SAR images, the effective using of DGPS data has important influence on the final accuracy and efficiency of surveying and mapping. This paper analyzed the imaging geometric characteristics of airborne SAR system, and, under the condition of space-constant PRF imaging technique, it put forward to a kind of flight track processing method for radar...
How to resist geometry transformation attacks effectively has become a focus of digital watermarking. In this paper a video blind watermarking algorithm resistant to geometry transformation attacks is proposed. In the scheme of watermark embedding, video shot segmentation is used first. Then, background of a video segment in the video shot is extracted by independent component analysis(ICA). Finally,...
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