- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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[IEEE 2018 25th IEEE International Conference on Image Processing (ICIP) - Athens, Greece (2018.10.7-2018.10.10)] 2018 25th IEEE International Conference on Image Processing (ICIP) - Distortion-Robust Spherical Camera Motion Estimation via Dense Optical Flow
摘要： Conventional techniques for frame-to-frame camera motion estimation rely on tracking a set of sparse feature points. However, images taken from spherical cameras have high distortion which can induce mistakes in feature point tracking, offsetting the advantage of their large fields-of-view. Hence, in this research, we attempt a novel approach of using dense optical flow for distortion-robust spherical camera motion estimation. Dense optical flow incorporates smoothing terms and is free of local outliers. It encodes the camera motion as well as dense 3D information. Our approach decomposes dense optical flow into epipolar geometry and the dense disparity map, and reprojects this disparity map to estimate 6DoF camera motion. The approach handles spherical image distortion in a natural way. We experimentally demonstrate its accuracy and robustness.
关键词： Optical flow,Spherical vision,Distortion
更新于2025-09-10 09:29:36
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Camera Calibration: An Overview of Concept, Methods and Equations
摘要： Camera calibration is favored as an important issue in photogrammetry and computer vision literatures. The importance of this issue can be due to two reasons: firstly, every recently camera should be calibrated before being used to correct its lens distortion and interior orientation elements. In addition, it is a main preprocessing step at many vision applications. This paper aims to provide an overview of concept, objective, methods and mathematical equations for camera calibration.
关键词： Self–Calibration,Photogrammetry,Interior Orientation Elements,Camera Calibration,Lens Distortion,Exterior Orientation Elements,Computer Vision
更新于2025-09-10 09:29:36
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RoF system based on phase modulator-employing polarization for linearization
摘要： In this paper, an analytical model is represented to analyze and improve the performance of radio over fiber (RoF) links against nonlinear distortion. RoF transmission link comprised of a phase modulator, polarizer and optical filter is considered. By controlling angles of polarization, the signals are fed to the modulator. Polarizer helps to suppress intermodulation distortion along the considered link. Performance is found in terms of spurious-free dynamic range (SFDR). Results show an improvement of 7.5-dB in SFDR for a polarized link in comparison with the conventional link.
关键词： Polarizer,IMD,SFDR,RoF,Nonlinear distortion
更新于2025-09-10 09:29:36
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The new ordered double perovskite SrLaCuIrO6
摘要： The new fully rock-salt ordered Ir5+ double perovskite SrLaCuIrO6 was synthesized, and its structural, magnetic and electronic properties were investigated. The compound crystallizes tetragonally (space group I4/m). The Cu2+ cation leads to strong Jahn-Teller distortion of the CuO6 octahedra. The compound shows semiconducting behavior with an estimated band gap of approximately 0.2 eV. At around 10 K a magnetic transition is observed.
关键词： D. Magnetic properties,E. High-temperature synthesis,A. Double perovskite,D. Jahn-Teller distortion
更新于2025-09-10 09:29:36
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Temporal-Spatial Varying Background Ionospheric Effects on the Moon-Based Synthetic Aperture Radar Imaging: A Theoretical Analysis
摘要： The Moon-based synthetic aperture radar (SAR) potentially offers an unprecedented high temporal resolution and wide spatial coverage, simultaneously, for Earth observation. However, the complex geometry in relating Moon-SAR-Earth motion where both the Earth’s rotation and lunar revolution exert, poses a great challenge in signal processing and image formation. Besides, the background ionospheric effects contributing to the phase dispersion become even more critical because the ionospheric freezing model usually assumed in the low earth orbit (LEO) SAR imaging is no longer valid for the Moon-based SAR, and the curved trajectory induced by the ultra-long synthetic aperture time further complicates the background ionospheric effects. In this paper, we investigate such effects on the Moon-based SAR imaging by establishing an accurate curved trajectory signal model. The image shift and image defocus caused by the temporal-spatial varying background ionosphere are evaluated in detail. Numerical analysis shows that the range shift can be up to hundreds of meters, while the azimuth shift is much less, on the order of tens of meters. As for image quality, the range defocusing is persistently significant, and yet the azimuth focusing is only slightly disturbed. Under the presence of background ionosphere, the geometric distortion and image defocusing given rise to a Moon-based SAR deserve a special care in the context of image quality.
关键词： Moon-based SAR,image defocusing,background ionospheric effects,geometric distortion
更新于2025-09-10 09:29:36
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[IEEE 2018 IEEE International Conference on System, Computation, Automation and Networking (ICSCAN) - Pondicherry, India (2018.7.6-2018.7.7)] 2018 IEEE International Conference on System, Computation, Automation and Networking (ICSCA) - Power Factor Correction in Z-Source Resonant Converter for Wireless Power Transfer Applications
摘要： In this paper the Z-source converter is introduced to power factor correction (PFC) applications. The concept is demonstrated through a wireless power transfer (WPT) system for electric vehicle battery charging, namely Z-source resonant converter (ZSRC). Due to the Z-source network (ZSN), the ZSRC inherently performs PFC and regulate the system output voltage simultaneously, without adding extra semiconductor devices and control circuitry to the conventional WPT system such as conventional PFC converters do. In other words, the ZSN can be categorized as a family of the single stage PFC converters. In addition, the ZSN is suitable for high power applications since it is immune to shoot-through states, which increases reliability and adds a boost feature to the system. The ZSRC-based WPT system operating principle is described and analyzed in this paper. Simulations, and experimental results based on a 1-kW prototype with 20-cm air gap between the system primary and secondary side are presented to validate the analysis, and demonstrate the effectiveness of the ZSN in the PFC of the WPT system.
关键词： Power factor correction (PFC),Wireless Power Transfer (WPT),Total Harmonic Distortion (THD),Z-source resonant converter (ZSRC),Series resonant converter (SRC)
更新于2025-09-10 09:29:36
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[IEEE 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - Paris, France (2018.7.8-2018.7.13)] 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - Modeling the Nonlinear Amplifier with the Pulse-Driven AC Josephson Voltage Standard
摘要： Behavior models of electronic components are critical in many metrological and measurement areas. This paper uses a two-tone signal synthesized by the pulse-driven ac Josephson voltage standard to achieve the input/output behavior of a nonlinear amplifier. Three Volterra series models including the memory polynomial model, general memory polynomial model, and dynamic deviation reduction model are analyzed and in detail. The result demonstrates the high performance of the achieved mathematical models.
关键词： Amplifier distortion,linearization techniques,pulse-driven ac Josephson voltage standard,signal synthesis,modeling
更新于2025-09-10 09:29:36
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[IEEE 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - Paris, France (2018.7.8-2018.7.13)] 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - Helium-Based Refractometry for Pressure Measurements in the Range 1–100 kPa
摘要： This paper describes an alternative of pressure measurements based on a helium absolute refractometer at 532 nm. The Fabry-Perot cavity has been characterized from relevant parameters and the resolution in pressure of this new optical pressure sensor is lower than 0.2 Pa.
关键词： Pressure-induced distortion coefficient,Coefficient of thermal expansion,Refractometry,Fabry-Perot cavity,Pressure sensor
更新于2025-09-10 09:29:36
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5.4: New RGBW Mapping Algorithm with Minimized Color Distortion
摘要： This paper proposed a novel RGB-to-RGBW mapping algorithm with minimized color distortion. This algorithm ensures that the color distortion of RGBW display is minimized by keeping the color coordinate remain unchanged from the original color. The proposed method primarily consists of three procedures. Step 1: Calculate the CIE chromaticity coordinates (x, y) and luminance (Y) of the input signal in the RGB display system. Step 2: Calculate the value of W0 based on the distance between the target color and the white point. Step 3: According to the color coordinate of the target color (x, y) and the color conversion model of multi-primary-color system, calculate the RGBW signal value of the target color in the RGBW display system. The comparison of test images shows that the algorithm is more effective in maintaining the saturation and hue of the original image than the traditional method.
关键词： RGBW display,Color conversion model of Multi-primary-color Display,Color distortion
更新于2025-09-10 09:29:36
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[Lecture Notes in Networks and Systems] Renewable Energy for Smart and Sustainable Cities Volume 62 (Artificial Intelligence in Renewable Energetic Systems) || Sliding Mode Control of DFIG Driven by Wind Turbine with SVM Inverter
摘要： In this paper, a direct Sliding Mode Control (SMC) of Doubly Fed Induction Generator (DFIG) driven by wind turbine with Space Vector Modulation (SVM) inverter is presented. The SMC is used to track the stator active and reactive power their references. The SVM inverter is used to improve the quality of the energy generated by DFIG which allows the minimizing of stator current harmonics and wide linear modulation range. Simulation results show that the proposed control give good performance and good quality of the energy where the THD of the stator current of the DFIG has small value.
关键词： Total Harmonic Distortion,Doubly Fed Induction Generator,Space Vector Modulation,Sliding Mode Control,Wind Turbine
更新于2025-09-10 09:29:36