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Common tasks of High-Frequency Surface Wave Radars (HFSWRs) are long-range ocean state monitoring and maritime surveillance for surface vessel detection. Heterogeneous background composed of sea clutter, external noise and other kind of clutter, the application of the classical Constant False Alarm Rate (CFAR) algorithms results in a high probability of false alarm and poor detection performance....
The performance of adaptive beamforming degrades severely when the strong desired signal is present in training snapshots with model mismatch. A robust adaptive beamforming is proposed using interference covariance matrix reconstruction in this paper. In the proposed method, the eigenvalue and eigenvector of desired signal is determined by calculating the correlation coefficients between eigenvectors...
A Doppler-range spectrum region segmentation method for Over-the-Horizon Radar (OTHR) is proposed as a preprocessor for the following signal processing. The method derives from the well-known Kullback-Leibler (KL) Divergence which measures dissimilarity between the sea clutter and atmosphere noise. By thresholding the bias of KL map it is estimated by a statistical and variational multiphase level...
Radar target recognition typically uses feature sets derived from high resolution range profile as an input to a classifier. The scattering centers can approximately model the radar optical region target. Therefore, the radar target recognition based on scattering centers of high resolution range profile has drawn more and more interests in recent years and a lot of methods has been proposed. However,...
Polarimetric information can fully reflect the electromagnetic scattering characteristics of radar target. Compact polarization, which can reduce the system complexity while preserving the polarimetric information, has become an important technique of getting polarimetric information in recent years. In this paper we propose a modified implementation for π/4 compact polarimetric mode radar, where...
The monopulse angle measuring technique is widely adopted in radar systems due to its simplicity and speed in accurately acquiring a target angle. However, in a spatial adaptive array, the beam distortion incurred by adaptive beamforming, can result in severe performance deterioration. A novel constrained monopulse angle measuring algorithm is proposed in this paper for spatial adaptive arrays. This...
A wideband Yagi antenna used for THz integrated application has been successfully developed. The antenna is constructed by some air-gap Coplanar Waveguides (CPW) with different length. The air-gap CPWs are realized by the air bridge technology. A semiinsulating SiC substrate with thickness of 50um is used as the supporter of antenna. Due to the use of the air-gap CPW, the affection of substrate can...
In this paper, a coarse-grained reconfigurable computing unit (RCU) is designed for the heterogeneous multi-core system (HMCS) which is applied to high density computing field. As a data-driving computing unit, RCU can work in two modes: stream-mode and store-mode. In first, it achieves a higher efficiency, while in latter it attains a better flexibility. The architecture of RCU is optimized for some...
This paper put forward a piecewise quadratic Lyapunov functions approach combined with time information to analysis hybrid systems' stability issues. The piecewise quadratic Lyapunov functions can be continuous or discontinuous, and with the aid of time information, we can let the piecewise quadratic Lyapunov functions increase to some extent. The search of piecewise quadratic Lyapunov functions are...
A new temporal sampling method for human action recognition using depth maps is proposed. The depth map frames are projected onto three orthogonal Cartesian planes respectively and the absolute difference between two successive projected ones is stacked to form the motion energy. Three sub-action frame sequences are selected accordingly, which constructs Adaptive Temporal Sampling (ATS) descriptor,...
In order to enhance the cell coverage and achieve the higher spectral efficiency, the concept of Heterogeneous Networks (HetNets) has been proposed in LTE-Advanced standardizations. In Macro-Pico HetNet scenario, Pico-eNBs are typically deployed within the coverage areas of Macro-eNBs. The setup details of Pico-eNBs (such as the number of Picos, transmit power, and hotspots distribution) will influence...
For miniaturization the microwave communication equipment, a miniaturized and low cost array antenna is proposed. A 2-layer of patch antenna unit is designed to broaden the bandwidth of the microstrip antenna. The CST MWS is used to simulate and optimize the antenna structure. Based on the designed antenna unit, an array antenna is proposed to achieve high gain, and the simulation and optimization...
In recent years, the use of nonlinear ultrasound in medical and industrial applications has increased rapidly. Harmonic signals, generated from nonlinear distortion of ultrasonic wave propagation in fluid or solid media, play an important role not only in ultrasonic medical imaging to provide higher resolution and higher contrast to tissue ratio, but also in nondestructive testing of fatigue cracks...
Radar High Resolution Range Profile (HRRP) represents the radial distribution of target scattering centers on radar line of sight, which infers something about target structure signatures. In this paper, the method of HRRP target recognition based on Gradient Boosting Decision Tree (GBDT) is proposed and the method how to choose model parameters is investigated. The experimental results from measurement...
The split-and-project method is introduced to modeling the 3D objects with rough surfaces. With this method, the blunt-nosed cone (BNC) and delta-wing aircraft (DWA) are taken as examples to build the rough objects. The bi-static RCS of the rough objects are then simulated through Physical Optics (PO) method under different correlation length and root-mean-square (rms) height. Results indicate that...
RCS of a waving target with uniform rough distribution is calculated by Physical Optics (PO) Method in Ka and Terahertz Bands respectively. So is another assembly consisting of a cylinder and a little cubic. The results show that the RCS of the two targets are different both in amplitude and symmetry. For a certain target, the results demonstrate that EM wave in terahertz band has a higher resolution...
In this paper, the electrical equivalent circuits of the piezoelectric transformer (PT) with heat transfer system (HTS) had been studied. A heat transfer model of the longitudinal vibration PT had been built and an experiment study on the equivalent circuit model of the PT with HTS was proposed. this work provides a useful information for the application of piezoelectric transformer in high-power...
The realization of automatic frequency tracking is of great significance in ultrasonic transducer due to its wide application area in nowadays industrial manufacture. However, excessive overshoot current, serious overheating and long response time remain the urgent issue. To tackle these existing ultrasonic frequency tracking problem, this paper proposes a hybrid technique that integrates fuzzy control...
A hybrid distributed generation system (HDGS) using a multi-input multi-output positive buck-boost converter (MIMO-PBBC) is proposed for the supply-side of the grid-connected photovoltaic (PV) generation power plant, where three PV clusters, one battery bank, and one supercapacitor module are hybridized and regulated by a centralized three-phase dc-ac inverter with their corresponding control systems...
Content-Centric Networking (CCN) proposals rethink the communication model around named data. In-network caching is a fundamental feature to distinguish the CCN from the current host-centric IP network. Caching scheme by hash-routing is a prominent solution as it enables a joint consideration of content placement and request-to-cache routing through a hash function, and therefore, makes the cached...
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