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oe1(光电查) - 科学论文

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  • [IEEE 2018 International Conference on Radar (RADAR) - Brisbane, Australia (2018.8.27-2018.8.31)] 2018 International Conference on Radar (RADAR) - Real Aperture Imaging Using Sparse Optimisation with Application to Low-Angle Tracking

    摘要: Estimating the angle of arrival of a low-altitude target over the sea surface is made difficult due to the coherent multipath interference caused by the target image. A real aperture imaging technique for estimating azimuth and elevation of targets using a phased array multichannel radar, as described by Berry et al [1], is applied to this classical problem of suppressing low-angle multipath signals received by a naval radar from a low-flying target. The degree of spatial resolution which can be usefully attained is explored; this depends on many factors and the nonlinear problem formulation is not easily amenable to analysis. It is found that the technique is feasible for resolving the direct target signal, its specular reflection and multiple diffuse reflections even when the signals would be combined by a conventional beamformer to form a multipath null.

    关键词: radar signal processing,low-angle tracking,sparse optimisation,multipath propagation,phased array multichannel radar

    更新于2025-09-23 15:22:29

  • [IEEE 2018 IEEE 10th Sensor Array and Multichannel Signal Processing Workshop (SAM) - Sheffield (2018.7.8-2018.7.11)] 2018 IEEE 10th Sensor Array and Multichannel Signal Processing Workshop (SAM) - An Alternating Minimization Approach to Optimizing Subarray Configuration for a Large Phased Array

    摘要: A large size phased array is a powerful system for surveillance, but must be appropriately decomposed as subarrays for efficient digital beamforming. One fundamental question is how to configure a large array as subarrays to satisfy various signal processing requirements. This work deals with two basic signal processing tasks, synthesizing multiple beams at subarray level and adaptively suppressing multiple interferences. Two optimization criteria to jointly design subarray configuration and digital weights for subarrays are proposed. To handle the large number of variables in the optimization formulations, we propose an alternating minimization approach with low computation cost. Numerical simulations are presented to demonstrate the effectiveness of the proposed algorithm.

    关键词: beamforming,Phased array,alternating optimization,subarray

    更新于2025-09-23 15:22:29

  • [IEEE 2018 IEEE 10th Sensor Array and Multichannel Signal Processing Workshop (SAM) - Sheffield (2018.7.8-2018.7.11)] 2018 IEEE 10th Sensor Array and Multichannel Signal Processing Workshop (SAM) - Interferometric Array Design Under Regularized Antenna Placements for Interference suppression

    摘要: Interference suppression is an important task in extensive sensor array applications, including large interferometric arrays in radio astronomy. The interferometric array design in terms of maximizing output signal-to-interference-plus-noise ratio (MaxSINR) calls for freely placing antennas on grid points without imposing any regularity conditions on the array structure. The configured sparse array exhibits multiple drawbacks, most notably, uncontrollable beampatterns with high sidelobes. To overcome these shortcomings, we add conventional beampattern sidelobe constraints in the design formulation. The resulting array is referred to as restricted beampattern array configuration (RBAC). Alternatively, we consider a new regularized placement array configuration (RPAC) strategy, where antenna position constraints are imposed as means for sidelobe control. In this case, the antenna selection is performed such that each segment of grid points must include one antenna, preventing very large inter-element spacing. We formulate the new RPAC problem and compare its solution to that of the RBAC.

    关键词: Sidelobe Suppression,Beampattern,Interferometric Array,Regularized Sensor Placement

    更新于2025-09-23 15:22:29

  • [IEEE 2018 IEEE International Students' Conference on Electrical, Electronics and Computer Science (SCEECS) - Bhopal (2018.2.24-2018.2.25)] 2018 IEEE International Students' Conference on Electrical, Electronics and Computer Science (SCEECS) - Solar Power Based Three-Level Neutral Clamped Inverter Fed DTFC-SVM of an IM Drive

    摘要: This paper presents a solar power based three-level neutral clamped inverter (3LNCI) fed induction motor drive (IMD) with space vector modulation based direct torque and flux control (DTFC-SVM) for the water pumping applications. Due to the robustness and the flexible operating characteristics, induction motor is most suitable for water pump system. A DC/DC boost converter along with perturb and observe method of maximum power point tracking (MPPT) control technique is employed to draw sophisticated power from the solar photovoltaic (PV) array. The DTFC-SVM of an IMD using 3LNCI is proposed for improving performance and reducing the ripple contents of torque, flux and stator currents. The proposed method is simulated in MATLAB/SIMULINK environment and simulated results are presented under various operating conditions.

    关键词: photovoltaic array,space vector modulation,induction motor drive,three-level diode clamped inverter,Direct torque and flux control

    更新于2025-09-23 15:22:29

  • Mixed-metal organic framework-coated ZnO nanowires array for efficient photoelectrochemical water oxidation

    摘要: Designing of high-performance photoanodes is essential for efficient solar energy conversion in photoelectrochemical (PEC) water splitting. Herein, we report an effective approach to synthesize three dimensional (3D) mixed-metal organic framework-coated ZnO nanowires array (ZnNi MOF@ZnO) for the effective PEC performance. The ZnO nanowires act as photon absorber as well as rapid charge transporter; whilst the ZnNi MOF provides the active sites for PEC process by lowering the energy barrier of water oxidation and suppressing electron-hole recombination. The 3D nanostructure of ZnNi MOF@ZnO nanowires array provides intimate interfacial contact through covalent interactions between the ZnNi MOF and ZnO nanowires which facilitates the rapid charge transfer during photocatalytic oxygen evolution reactions. As a result, the ZnNi MOF@ZnO nanowires array exhibited excellent photoelectrochemical water oxidation with very low onset potential (0.31 V vs. RHE) and high photocurrent density (1.40 mA/cm2) as compared to the Zn MOF @ZnO and ZnO nanowires array. This facile strategy provides a promising direction towards high performance photoanode design for adequate solar energy conversion.

    关键词: Metal organic frameworks (MOFs),Photoelectrocatalyst,Nanowires array,Photoelectrochemical water oxidation,Photoanodes

    更新于2025-09-23 15:22:29

  • LLMLF based Control Approach and LPO MPPT Technique for Improving Performance of a Multifunctional Three-Phase Two-Stage Grid Integrated PV System

    摘要: This study presents a novel Leaky Least Mean Logarithmic Fourth (LLMLF) based control technique and Learning based Perturb and Observe (LPO) maximum power point tracking (MPPT) algorithm, for optimal control of grid-tied solar photovoltaic (PV) system. Here, a novel LLMLF algorithm is developed for active component extraction from load current, and a novel LPO MPPT algorithm is developed for optimal MPPT operation. Proposed LPO is the improved form of Perturb and Observe (P&O) algorithm, where inherent problems of traditional P&O algorithm like steady-state oscillation, slow dynamic responses and fixed step size issues, are successfully mitigated. The prime objective of proposed LLMLF control is to, fulfill the active power requirement of the loads from generated solar PV power, and excess power is fed to the grid. However, when generated PV power is less than the required load power, then LLMLF fulfills the load by taking extra required power from the grid. During this process, power quality is improved at the grid. The controller action provides reactive power compensation, power factor correction, harmonics filtering and mitigation of other power quality issues. Moreover, when the solar irradiation is zero, than the DC link capacitor and VSC act as DSTATCOM (Distribution Static Compensator), which enhances the utilization factor of the system. The proposed techniques are modeled and their performances are verified experimentally on a developed prototype, in solar insolation variation condition, imbalance loading condition for linear/nonlinear loads, as well as in different grid disturbances such as over-voltage, under-voltage, phase imbalance, harmonics distortion in the grid voltage etc, where it has shown a very good performance.

    关键词: Leaky Least Mean Logarithmic Fourth Control,Solar PV array,Grid Integrated,Power Quality,DSTATCOM

    更新于2025-09-23 15:22:29

  • [IEEE 2018 IEEE Western New York Image and Signal Processing Workshop (WNYISPW) - Rochester, NY, USA (2018.10.5-2018.10.5)] 2018 IEEE Western New York Image and Signal Processing Workshop (WNYISPW) - INCREMENTAL COMPLEX L1-PCA FOR DIRECTION-OF-ARRIVAL ESTIMATION

    摘要: In wireless-node localization, the receiver processes snapshots collected by its antenna array in order to estimate the direction-of-arrival (DoA) of a source of interest. High-resolution direction finding is commonly carried out by principal-component analysis (PCA) of the collected complex-valued snapshots (subspace-based methods). Standard PCA was recently replaced by corruption-resistant L1-PCA in order to counteract the detrimental impact of unexpected, intermittent jamming. In this paper, we present the first incremental method for complex L1-PCA and employ it for online direction finding, as snapshots naturally arrive in a streaming fashion. Our numerical studies corroborate the computational efficiency and jamming/corruption resistance of the proposed method.

    关键词: SVD,Array processing,corrupted data,L1-norm,L1-PCA,direction finding

    更新于2025-09-23 15:22:29

  • [IEEE 2018 IEEE International Workshop on Electromagnetics: Applications and Student Innovation Competition (iWEM) - Nagoya (2018.8.29-2018.8.31)] 2018 IEEE International Workshop on Electromagnetics:Applications and Student Innovation Competition (iWEM) - Functional Microstrip Array Antenna Integrating Double-Sided MIC's

    摘要: In this paper, functional microstrip array antennas are demonstrated. The double-sided MIC is effectively utilized to realize the functions with a simple structure. Dual circular polarization and CP sense switching capability are achieved on a single-layer substrate.

    关键词: microstrip array antenna,double-sided MIC,dual-polarization

    更新于2025-09-23 15:22:29

  • [IEEE 2018 IEEE International Workshop on Electromagnetics: Applications and Student Innovation Competition (iWEM) - Nagoya (2018.8.29-2018.8.31)] 2018 IEEE International Workshop on Electromagnetics:Applications and Student Innovation Competition (iWEM) - The R&D of Low-Profile Electronically Scanned Array Antenna for Aircraft

    摘要: Demand has been increasing for better mobile phone and Internet access for people on board aircraft. National Institute of Information and Communications Technology (NICT) research and develop the high performance active electronically scanned array (AESA) antenna for regional jet in Ka band. This report shows the results that 16 elements array antenna was fabricated and evaluated as a fundamental study of the transmission side configuration of AESA for aircraft.

    关键词: Aircraft,Active Electronically Scanned Array (AESA) Antenna,Ka-bands

    更新于2025-09-23 15:22:29

  • Faulty elements diagnosis of phased array antennas using a generative adversarial learning-based stacked denoising sparse autoencoder

    摘要: Diagnosis of faulty elements in a linear phased array antenna is of great importance in the wireless communication field which has been received increasing attention. As a result of element or elements failure in the linear phased array antennas, the whole radiation pattern will suffer from high side lobe levels, wide bandwidth and unexpected nulls. To this end, we suggest a novel approach by combining the generative adversarial learning and the stacked denoising sparse autoencoder to determine the location of the faulty elements in antennas. The suggested approach can learn discriminative features from radiation pattern images adaptively and automatically with less expert knowledge. Meanwhile, the suggested approach is able to overcome the strong noise, the high dimensional size of the radiation pattern and the small fault samples. In this regard, the suggested approach possesses superiority in discriminant capability in contrast to the existing related approaches.

    关键词: stacked denoising sparse autoencoder,phased array antennas,Faulty elements diagnosis,generative adversarial learning

    更新于2025-09-23 15:22:29