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[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Monte Carlo Analysis of Orbital Station Motion Parameter Errors Influence on Sar Azimuth Resolution Degradation
摘要： Orbital stations can be an alternative platform choice for SAR payloads besides professional remote sensing satellite platform. However, such platform cannot provide as precision motion parameters as remote sensing satellite platform for SAR imaging due to its unique structure. The influence of motion parameter errors on SAR azimuth resolution degradation should be taken into consideration. Selecting the second order phase error caused by Doppler frequency rate with error as intermediate variable between motion parameter errors and SAR azimuth resolution, this paper proposed a Monte Carlo simulation model has been set up to obtain the specific probability distribution of SAR azimuth resolution degradation. A typical Monte Carlo simulation result is given to show the effectiveness of the method and may help actual SAR payload system design.
关键词： Orbital Station,Monte Carlo,SAR,Azimuth Resolution Degradation,Motion Parameter Errors
更新于2025-09-23 15:22:29
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[IEEE 2018 China International SAR Symposium (CISS) - Shanghai (2018.10.10-2018.10.12)] 2018 China International SAR Symposium (CISS) - High-Squint SAR Imaging for Noncooperative Moving Ship Target Based on High Velocity Motion Platform
摘要： For high velocity motion platform, it usually takes a shorter azimuth accumulation time to achieve high-squint synthetic aperture radar (SAR) imaging for noncooperative moving ship target with meter-level resolutions. In this case, three-dimensional relative motion of the ship target can be neglected approximately, mainly the translational motion should be considered. However, the magnitude and direction of the target's translational velocity are unknown. To solve the above problem, a two-step imaging method is proposed in this paper. Firstly, the entire scene is coarsely imaged by using the parameters provided by inertial navigation system. The position of the ship target can be judged by two-dimensional order statistics constant false alarm rate (OS-CFAR) detection and ship target pixel clustering. By constructing the band-pass filter in azimuth frequency domain, the data of the target can be obtained effectively, and to a certain extent, sea clutter and noise are suppressed. Then the motion parameters are estimated. Finally, the target is secondarily imaged with the estimated parameters to achieve precise focus. The results of simulation verify the correctness of the analysis and the validity of the proposed method.
关键词： noncooperative moving ship target,motion parameter estimation,high-squint SAR,two-step imaging method
更新于2025-09-23 15:22:29
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[IEEE 2018 IEEE Asia-Pacific Conference on Antennas and Propagation (APCAP) - Auckland (2018.8.5-2018.8.8)] 2018 IEEE Asia-Pacific Conference on Antennas and Propagation (APCAP) - Maximum efficiency analysis in wireless power transfer
摘要： The optimum design of loosely coupled transformer is the key technique in the wireless power transfer system (WPT). An improved magnetic model based on partial element equivalent circuit (PEEC) method is proposed in this paper. All parts of magnetic flux are divided into four categories: 1) flyback to topology; 2) resonant to topology; 3) quasi-resonant to topology; and 4) self-resonant to topology. As becomes clear from previous discussion, the converter topology used must be able to tolerate the minimum copper loss and minimum number of turns in given power transformer capability. In this method, the preferred parameters are coil shape and dimension, operating frequency, and coupling coefficient. The validity of the optimization algorithm is verified by experimental results.
关键词： reluctance model,parameter optimization,partial element equivalent circuit method,wireless power transfer,Prime-Mal
更新于2025-09-23 15:22:29
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[IEEE 2018 IEEE International Conference on Electrical Engineering and Photonics (EExPolytech) - Saint Petersburg, Russia (2018.10.22-2018.10.23)] 2018 IEEE International Conference on Electrical Engineering and Photonics (EExPolytech) - Band-Pass ARC-Filter Based on the Classical Wien Bridge with the Pole Frequency Rise and Independent Adjustment of the Main Parameters
摘要： A new topology of the band-pass active RC filter (BP) based on the classic Wien bridge is proposed. This scheme, implemented on two Op-Amps, is recommended for the use as a second-order link in more complex BPs. The analysis of the modified band-pass ARC filter is carried out, the main parameters of the BP are found. The computer simulation of the developed PF tuning algorithm is completed. The graphs of changes in the frequency response and phase response when changing various parameters of the BP are obtained. It is shown that in the considered BP an independent adjustment of the main parameters is ensured - transmission coefficient in the passband, pole attenuation and pole frequency.
关键词： ARC filter,trimming,active RC filter,band-pass RC filter,high-order BP,Wien bridge,parameter adjustment
更新于2025-09-23 15:22:29
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Simulated performance analysis of a solar aided power generation plant in fuel saving operation mode
摘要： Solar aided (coal-fired) power generation (SAPG) system has been proved to be an efficient way to utilize the solar energy for power generation. Due to the instability of the solar radiation, a SAPG system generally operates under transient working conditions. In this paper, performance simulation sub-models of main components in a SAPG plant are established based on the lumped parameter assumption. A 330 MW SAPG power plant as a case study is simulated. The variations of the performances, main parameters of the plant with the solar field heat output and the dynamic responses under a typical day are analyzed. The results show that when the heat output of the solar field changes from 0 kJ/h to 2.13 × 108 kJ/h, the coal saving rate will increase to 6.4%, and the solar power generation share (the proportion of the power from the solar energy to the total power from the SAPG plant) will increase to 7.74%. During the analysis process, in order to optimize the solar field, the concept of the solar field equivalent efficiency (SFEE) is proposed and the optimal velocity of heat transfer fluid (HTF) in absorber tube is obtained.
关键词： Optimize design,Dynamic responses,Solar aided coal-fired power generation,Parameter variation
更新于2025-09-23 15:21:21
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A Parameter Estimation based MPPT Method for a PV System using Lyapunov Control Scheme
摘要： There are two types of external variations which change the operating point of a photovoltaic (PV) system: one is environmental change caused by variation in temperature and/or irradiance and the other is load change. The variation in environmental condition changes the PV array characteristic itself whereas the load variation changes the operating point within the same curve. Each type of change can be uniquely identified using history of PV voltage and current measurements. Using the above fact, this paper proposes a fast maximum power point tracking (MPPT) technique for PV array coupled with boost converter. The proposed method determines MPP in a single step by finding out temperature and irradiance at which the PV array is operating. Furthermore, based on the measured values of PV voltage and current, inductor current and load voltage are also calculated, eliminating the need for additional sensors. Lyapunov based controller (LBC) is implemented to track inductor current to its desired value and find the desired duty cycle to reach MPP. The proposed method is validated by both simulation and experimental results under varying temperature, irradiance and load condition. A comparison with the existing MPPT method is also presented in order to show the efficacy of the proposed method.
关键词： MPPT,DC-DC converters,Lyapunov Function,Incremental Conductance,PV cell,Parameter Estimation
更新于2025-09-23 15:21:21
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Assessment of Fringe Pattern Decomposition with a Cross-Correlation Index for Phase Retrieval in Fringe Projection 3D Measurements
摘要： Phase retrieval from single frame projection fringe patterns, a fundamental and challenging problem in fringe projection measurement, attracts wide attention and various new methods have emerged to address this challenge. Many phase retrieval methods are based on the decomposition of fringe patterns into a background part and a fringe part, and then the phase is obtained from the decomposed fringe part. However, the decomposition results are subject to the selection of model parameters, which is usually performed manually by trial and error due to the lack of decomposition assessment rules under a no ground truth data situation. In this paper, we propose a cross-correlation index to assess the decomposition and phase retrieval results without the need of ground truth data. The feasibility of the proposed metric is verified by simulated and real fringe patterns with the well-known Fourier transform method and recently proposed Shearlet transform method. This work contributes to the automatic phase retrieval and three-dimensional (3D) measurement with less human intervention, and can be potentially employed in other fields such as phase retrieval in digital holography.
关键词： parameter selection,cross-correlation,Fourier transform,phase retrieval,Shearlet transform,fringe pattern decomposition
更新于2025-09-23 15:21:21
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Real-Time Geometric Parameter Measurement of High-Speed Railway Fastener Based on Point Cloud from Structured Light Sensors
摘要： With the increase in the number of service years for high-speed railways, the foundation of the rail track suffers from settlement, which causes rail track irregularity. To adjust the position of the track and meet track regularity demands, several components of the fastening system will be replaced by different sized components. It is important to measure the exact geometric parameters for the components of a fastening system before adjusting the track. Currently, the measurement process is conducted manually, which is laborious and error-prone. In this paper, a real-time geometric parameter measurement system for high-speed railway fastener based on 2-D laser profilers is presented. Dense and precise 3-D point clouds of high-speed railway fasteners are obtained from the system. A fastener extraction method is presented to extract fastener point cloud and a region-growing algorithm is used to locate key components of the fastener. Then, the geometric parameter of the fastener is worked out. An experiment was conducted on a high-speed railway near Wuhan, China to verify the accuracy and repeatability of the system. The maximum root-mean-square-error between the manual measurement and the system measurement is 0.3 mm, which demonstrates adequate accuracy. This system can replace manual measurements and greatly improve the efficiency of geometric parameter measurements for fasteners.
关键词： fastener geometric parameter measurement,region grow,high-speed railway,dense point cloud,structured light sensor
更新于2025-09-23 15:21:21
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[Springer Theses] Electrical Properties of Indium Arsenide Nanowires and Their Field-Effect Transistors || Fabrication, Characterization and Parameter?Extraction of InAs Nanowire-Based Device
摘要： Nanofabrication, low noise electrical measurement and various nanoscale characterization methods are frequently used in the study. This chapter will give as introduction on the growth method, fabrication techniques, characterization methods of materials and devices, measurement systems, and way to extract the electrical parameters of InAs nanowires FET devices.
关键词： Parameter extraction,Fabrication of nanowire devices,Electrical measurement,Structural characterization
更新于2025-09-23 15:21:21
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[IEEE 2018 VII. Lighting Conference of the Visegrad Countries (Lumen V4) - Trebic, Czech Republic (2018.9.18-2018.9.20)] 2018 VII. Lighting Conference of the Visegrad Countries (Lumen V4) - Evaluation of Selected Parameters of Non-Directional Household Lamps
摘要： Currently, in place of traditional incandescent lamps, the user of home lighting has the option of using halogen lamps. The lamps, compact fluorescent commercial offer is very wide and diverse, both as to the types of lamps and their prices. Usually, when buying a lamp, the user is guided by the price and parameters given on the packaging. Unfortunately, all parameters on the product packaging only constitute the manufacturer's declaration and do not always correspond to actual parameters. The basic requirements for non-directional lamps for home use are contained in the regulations of the Commission of the European Community. However, only the initial parameters are usually verified. Due to the long duration of measurements, operational parameters are not controlled each time. The article presents the results of tests and analysis of lumen maintenance factor of selected non-directional lamps for home use after a defined period of operation. The quality of the tested lamps was assessed.
关键词： selected non-directional lamps for home use,lamp lumen maintenance factor,initial parameter of lamp
更新于2025-09-23 15:21:21