- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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[IEEE 2019 Radiation and Scattering of Electromagnetic Waves (RSEMW) - Divnomorskoe, Russia (2019.6.24-2019.6.28)] 2019 Radiation and Scattering of Electromagnetic Waves (RSEMW) - Diffraction of a Plane E-polarized Wave on Waveguide Van Atta Array, Placed on the Surface of PEC Cylinder
摘要： The two-dimensional problem of the diffraction of a plane E-polarized wave on a Van Atta waveguide array located on the surface of a perfectly-conducting circular cylinder is solved. The radiators in the form of open ends of waveguides are connected by plane-parallel multimode waveguides of uniform length. The task is reduced to solving an integral equation for the magnetic field vector over the entire surface of the cylinder, which is reduced to an infinite system of linear algebraic equations for the coefficients of the expansion of the magnetic field vector for a complex Fourier series in azimuthal harmonics. The solution of the equation was received strictly and approximately. An expression for the scattering diagram is obtained, represented through the geometrical parameters of the structure.
关键词： reflected wave,Van Atta array,scattering diagram,radar cross section,waveguide
更新于2025-09-23 15:21:01
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Single-pixel 3D reconstruction via a high-speed LED array
摘要： Three-dimensional reconstruction can be performed in many ways, among which photometric stereo is an established and intensively investigated method. In photometric stereo, geometric alignment or pixel-matching between two-dimensional images under different illuminations is crucial to the accuracy of three-dimensional reconstruction, and the dynamic of the scene makes the task difficult. In this work, we propose a single-pixel three-dimensional reconstructioning system utilizing structured illumination, which is implemented via a high-speed LED array. By performing 500kHz structured illumination and capturing the reflected light intensity with detectors at different spatical locations, two-dimensional images of different shadows with 64×64 pixel resolution are reconstructed at 122 frame per second. Three-dimensional profiles of the scene are further reconstructed using the surface gradients derived by photometric stereo algorithm, achieving a minimum accuracy of 0.50 mm. Chromatic three-dimensional imaging via an RGB LED array is also performed at 40 frame per second. The demonstrated system significantly improves the dynamic performance of the single-pixel three-dimensional reconstruction system, and offers potential solutions to many applications, such as fast three- dimensional inspection.
关键词： 3D reconstruction,LED array,single-pixel imaging
更新于2025-09-23 15:21:01
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[IEEE 2019 7th International Renewable and Sustainable Energy Conference (IRSEC) - Agadir, Morocco (2019.11.27-2019.11.30)] 2019 7th International Renewable and Sustainable Energy Conference (IRSEC) - A Genetic Algorithm based Improve P&O-PI MPPT Controller for Stationary and Tracking Grid-Connected Photovoltaic System
摘要： this paper deals the performance comparison and efficiencies of single-axis and dual-axis tracking PV system to an identical fixed-mount PV system for two typical clear sunny days (Ghardaia area), two typical days are chosen, the first day in winter and the second day in the summer. For the three types of PV systems, P&O-PI MPPT techniques optimized with a genetic algorithm is proposed. This paper has two different objectives. 1stly, a proposed MPPT technique has been presented to optimize P&O-PI controller via the GA technique to increase the tracking response of MPP with high efficiency and that improves the limitations of the traditional MPPT techniques. 2ndly, a performance comparison of efficiencies of single-axis and dual-axis tracking system and an identical fixed inclination system .Simulation results with MATLAB/SIMULINK are presented and discussed to verify the satisfactory performance of the proposed MPPT control, in which the optimized P&O-PI controller by GA algorithms gives the better performance. The simulation results also have shown that both single-axis and dual-axis are highly efficient in terms of the electrical energy output when compared to the fixed mount system. The results show the effectiveness of the tracking system of about 25% in energy efficiency.
关键词： grid,photovoltaic system,dual‐axis tracking,P&O-PI,fixed array,boost converter,Genetic algorithm,single axis tracking,MPPT control
更新于2025-09-23 15:21:01
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[IEEE 2019 IEEE Conference on Power Electronics and Renewable Energy (CPERE) - Aswan City, Egypt (2019.10.23-2019.10.25)] 2019 IEEE Conference on Power Electronics and Renewable Energy (CPERE) - Common-Mode Voltage Analysis of Three-phase Quasi-Z Source Inverters for Transformerless Photovoltaic Systems
摘要： Reducing the capacitance of programmable capacitor arrays (PCAs), commonly used in analog integrated circuits, is necessary for low-energy applications. However, limited mismatch data are available for small capacitors. We report mismatch measurement for a 2-fF poly–insulator–poly (PIP) capacitor, which is the smallest reported PIP capacitor to the best of the authors’ knowledge. Instead of using complicated custom on-chip circuitry, direct mismatch measurement is demonstrated and veri?ed using Monte Carlo simulations and experimental measurements. Capacitive test structures composed of 9-bit PCAs are implemented in a low-cost 0.35-μm CMOS process. Measured data are compared to the mismatch of large PIP capacitors, theoretical models, and recently published data. Measurement results indicate an estimated average relative standard deviation of 0.43% for the 2-fF unit capacitor, which is better than the reported mismatch of metal–oxide–metal (MOM) fringing capacitors implemented in an advanced 32-nm CMOS process.
关键词： programmable capacitor array (PCA),Analog-to-digital converter (ADC),energy-ef?cient circuits,mismatch characterization,capacitance-to-digital converter (CDC),capacitor mismatch
更新于2025-09-23 15:21:01
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[IEEE 2019 Device Research Conference (DRC) - Ann Arbor, MI, USA (2019.6.23-2019.6.26)] 2019 Device Research Conference (DRC) - Field Effect and Raman Characterization of Self-Assembled Mos <sub/>2</sub> Nanoscrolls
摘要： In bistatic multiple input multiple output (MIMO) radar, more number of detectable incident signals and a higher angle estimation performance can be obtained by using conjugate estimation of signal parameters via rotational invariance techniques (ESPRITs) with the characteristic of noncircularity. The result is achieved under the assumption that all the received signals are noncircular. When the incident signals are the coexistence of noncircular and circular signals, the conjugate ESPRIT will not valuable. Therefore, this paper proposes a method of the joint of direction of departure (DOD) and direction of arrival (DOA) estimation, which is appropriate for the coexistence of noncircular and circular signals in bistatic MIMO radar. First, the received data model of the bistatic MIMO radar is given. Second, we modify the received signal model by the use of noncircularity characteristic. Third, we derive out the equation of spatially rotational invariant containing the DOD and DOA information. Last, we solve the equation to obtain the DOD and DOA by means of total least squares technology. The proposed algorithm has the three advantages. One is that it has better angle estimation accuracy than that of method which does not use the noncircularity characteristic. Another one is that it has more number of detectable incident signals. The last one is that the more number of noncircular signals, the higher angle estimation accuracy will be. Results from numerical experiments are used to show the effectiveness of our proposed algorithm.
关键词： ESPRIT,noncircular,DOA estimation,MIMO radar,Array signal processing
更新于2025-09-23 15:21:01
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[IEEE 2019 European Space Power Conference (ESPC) - Juan-les-Pins, France (2019.9.30-2019.10.4)] 2019 European Space Power Conference (ESPC) - Electrostatic Discharge Tests for JUICE Photovoltaic Assembly
摘要： A nominally circular 2-D broadband acoustic array of 1.3-m diameter, comprising 508 sensors and associated electronics, was designed, built, and tested for ambient noise imaging (ANI) potential in Singapore waters. The system, named Remotely Operated Mobile Ambient Noise Imaging System (ROMANIS), operates over 25–85 kHz, streaming real-time data at 1.6 Gb/s over a fiber optic link. By using sensors that are much larger than half-wavelength at the highest frequency of interest, so with some directionality, good beamforming performance is obtained with a small number of sensors compared to a conventional half-wavelength-spaced array. A data acquisition system consisting of eight single-board computers enables synchronous data collection from all 508 sensors. A dry-coupled neoprene cover is used to encapsulate the ceramic elements as an alternative to potting or oil filling, for easier maintenance. Beamforming is performed in real-time using parallel computing on a graphics processing unit (GPU). Experiments conducted in Singapore waters yielded images of underwater objects at much larger ranges and with better resolution than any previous ANI system. Although ROMANIS was designed for ANI, the array may be valuable in many other applications requiring a broadband underwater acoustic receiving array.
关键词： broadband array design,Ambient noise imaging (ANI),data acquisition,underwater acoustics
更新于2025-09-23 15:21:01
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[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Femtosecond-laser photoemission spectroscopy for ultrafast photovoltage dynamics: limitations and possibilities
摘要： In this paper, we study the time-of-arrival (TOA) based self-calibration problem of dual-microphone array for known and unknown rack distance, and also for different combinations of dimension for the af?ne spaces spanned by the receivers and by the senders. Particularly, we analyze the minimum cases and present minimum solvers for the case of microphones and speakers in 3-D/3-D, in 2-D/3-D, and in 3-D/2-D, with given or unknown rack length. We identify for each of these minimal problems the number of solutions in general and develop ef?cient and numerically stable, non-iterative solvers. Solving these problems are of both theoretical and practical interest. This includes understanding what the minimal problems are and how and when they can be solved. The solvers can be used to initialize local optimization algorithms for ?nding the maximum likelihood estimate of the parameters. The solvers can also be used for robust estimation of the parameters in the presence of outliers, using, e.g., RANSAC algorithms. We demonstrate that the proposed solvers are numerically stable in synthetic experiments. We also demonstrate how the solvers can be used with the RANSAC paradigm. We also apply our method for several real data experiments, using ultra-wide-band measurements and using acoustic data.
关键词： dual-microphone array,Time-of-arrival (TOA),minimal solver,self-calibration
更新于2025-09-23 15:21:01
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[IEEE 2019 7th International Renewable and Sustainable Energy Conference (IRSEC) - Agadir, Morocco (2019.11.27-2019.11.30)] 2019 7th International Renewable and Sustainable Energy Conference (IRSEC) - Design and Performance Analysis of a Photovoltaic Water Pumping System based on DC-DC Boost Converter and BLDC Motor
摘要： This paper presents the modeling, control and optimization of a photovoltaic water pumping system. The system consists of a DC-DC Boost converter, which is used as a link between a Solar Photovoltaic (SPV) panels and the three-phase inverter (VSI) to feed the BLDC motor. A centrifugal pump is connected to this motor in order to use the water pumped afterwards to multiple applications. Maximum Power Point Tracking (MPPT) control techniques are an essential part of improving the efficiency of photovoltaic (PV) systems. It is principally used to extract maximum possible power of the PV modules under any condition of solar irradiation. For this reason, P&O algorithm is used due to its high performance and its simplicity of implementation. The DC-DC Boost converter, compared to the various common DC-DC converters (Buck, Buck-Boost, SEPIC, Cuk...) has many benefits in SPV based applications, such as limiting the starting current of the motors. Using a BLDC motor is found to be the best option because of its high efficiency and reliability, better performance, and requires low maintenance. The considered system as well as the control strategies has been implemented in MATLAB-Simulink environment. The results show the effectiveness of the studied photovoltaic water pumping system.
关键词： brushless DC electric motor,perturbation and observation,voltage source inverter,Boost converter,solar photovoltaic array,electronic commutation,centrifugal pump
更新于2025-09-23 15:21:01
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A generalised approach to calculate various transport observables for a linear array of series and parallel quantum dots
摘要： A systematic generalised approach to ?nd transport observables for a linear array of different quantum dot (QD) systems has been discussed, using non-equilibrium Green function (NEGF) formalism, in the presence of on-dot Coulomb interaction and inter-dot tunnelling. The equation of motion (EOM) method has been used to derive expressions for Green functions (GFs) within the simplest mean-?eld approximation to tackle the Coulomb correlation term. Starting from the mathematical structures of GFs for single, double and triple quantum dot systems, the expressions for GFs and transport observables have been generalised for the quantum dot systems containing N number of quantum dots in series as well as parallel linear array of dots. Further, the formulae so obtained have been used for numerical calculations of transmission probability and the I –V characteristics of linear arrays of quantum dots in series as well as parallel con?guration containing up to three dots. The results show that, with the increase in number of dots in the scattering region, transmission probability and electron current decrease in series case, while both quantities increase in parallel con?guration of dots. The inter-dot tunnelling leads to the splitting of transmission peaks in double QD system in series case whereas, it induces Fano effect in triple QD system in parallel con?guration.
关键词： quantum dots,Quantum transport,non-equilibrium Green function,Landauer–Buttiker formula,linear array of dots
更新于2025-09-23 15:21:01
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[IEEE 2019 IEEE Asia-Pacific Microwave Conference (APMC) - Singapore, Singapore (2019.12.10-2019.12.13)] 2019 IEEE Asia-Pacific Microwave Conference (APMC) - An Ultra Wideband Vivaldi Antenna Array Based on Tightly Coupled Effect
摘要： An ultra wideband Vivaldi antenna array based on tightly coupled effect is proposed. The elements are arranged overlap to get an additional capacitive capacity to achieve impedance matching at low frequency. A sample of a 4×4 Vivaldi array was simulated, fabricated, and tested. The measured farfield waveform is basically agreed with simulated one. The designed antenna gets a bandwidth of 0.4GHz-4.2GHz.
关键词： impedance matching,tightly coupled effect,Ultra wideband,Vivaldi antenna array
更新于2025-09-23 15:21:01