- 标题
- 摘要
- 关键词
- 实验方案
- 产品
过滤筛选
- 2018
- filtering responses
- compact size
- substrate integrated waveguide (SIW)
- Balun and balanced circuits
- Electronic Science and Technology
- South China University of Technology
-
[IEEE 2018 International Conference on Applied Engineering (ICAE) - Batam, Indonesia (2018.10.3-2018.10.4)] 2018 International Conference on Applied Engineering (ICAE) - Vision Based Flame Detection System For Surveillance Camera
摘要： Flame detection systems are useful for the development of fire early detection systems. In general, conventional fire detection system which is usually used heat detector cannot detect the presence of fire since the detector requires much time to detect temperature changes. The use of a camera as an image scanner sensor has the potential to be used as an identifier of a flame shape or color. This study aims to build an image processing flame detection system using image enhancement, segmentation and filtering methods which is applied the Vission Assistant available in LabVIEW. The system implemented in a frame rate of 30 fps with a resolution of 1024 x 768, in which the system accuracy reach up to 98%.
关键词： Image Enhancement,Color Filtering,LabVIEW,HSV Filtering,Flame Detection
更新于2025-09-23 15:23:52
-
Enhancement of objects in photoacoustic tomography using selective filtering
摘要： Here we developed a real-time photoacoustic tomography (PAT) imaging acquisition device based on the linear array transducer utilized on ultrasonic devices. Also, we produced a phantom including diverse contrast media and acquired PAT imaging as the light source wavelength was changing to see if the contrast media reacted. Indocyanine green showed the highest reaction around the 800-nm band, methylene blue demonstrated the same in the 750-nm band, and gold nanoparticle showed the same in the 700-nm band. However, in the case of superparamagnetic iron oxide, we observed not reaction within the wavelength bands used herein to obtain imaging. Moreover, we applied selective filtering to the acquired PAT imaging to remove noise from around and reinforce the object’s area. Consequentially, we could see the object area in the imaging was effectively detected and the image noise was removed.
关键词： Photoacoustic image,real-time,back projection algorithm,selective filtering,ultrasonic imaging
更新于2025-09-23 15:23:52
-
A novel method for simultaneous determination of zinc, nickel, cobalt and copper based on UV–vis spectrometry
摘要： A novel method based on UV–vis spectrometry is developed for simultaneous determination of zinc, nickel, cobalt and copper without any separation steps. The method studied in this paper is the combination of ratio spectra derivative and kalman filtering spectrophotometry. First, using absorbance of zinc standard solution as divisor, the ratio spectra derivative obtained can completely eliminate the interference of zinc on trace ions. Second, the trace ions are simultaneously determined by kalman filtering spectrophotometry. Last, based on obtaining trace ion concentrations, a calibration curve for zinc is established. The linear determination ranges are 10-70mg/L for zinc, 0.2-1.4mg/L for trace ions of nickel, cobalt and copper. The results show that the predicted results of zinc, nickel, cobalt and copper by this proposed method is superior to PLS method. The work reported here is an effective attempt for the simultaneous determination of zinc, nickel, cobalt and copper in industrial wastewater of zinc hydrometallurgy, and will have more applications.
关键词： Zinc hydrometallurgy,Ratio spectra derivative,Kalman filtering spectrophotometry,UV–vis spectrometry
更新于2025-09-23 15:23:52
-
Rapid mapping application of vegetated terraces based on high resolution airborne LiDAR
摘要： The aim of this work is to define a methodology for terraced areas survey and rapid mapping in a complex environment, like Ligurian (Northwestern Italy) one, where a remarkable percentage of its surface is estimated as terraced and where the canopy coverage makes their recognition very hard. Methodology steps are the definition of LiDAR survey parameters, morphometric filtering and GIS processing for final mapping. Each phase is oriented to provide a reliable terrace mapping, also practicable in canopy-covered areas due to a particular attention to land cover influence. The work considers a case study (Rupinaro basin) close to Cinque Terre, with a mixed land cover (terraces, forest and urbanized areas). The methodology provided encouraging results detecting 448 ha of terraces, 95% of them located under canopy cover. This finding pointed out that terraces mapping cannot rely only on photo-interpretation, as canopies will hamper their detection. Mapping of these areas, frequently characterized by abandonment, is crucial while identifying potential trigger factors for slope instabilities. This case study highlighted the importance of a carefully planned production chain, that should start from LiDAR survey parameter choice, providing the best input for analysis algorithm and providing the correct identification of terraces.
关键词： land abandonment,high resolution Digital Terrain Model,rapid mapping,Anthropic landscape,morphometric filtering
更新于2025-09-23 15:23:52
-
Singular spectrum analysis filtering and Fourier inversion: an efficient and fast way to improve resolution and quality of current density maps with low-cost Hall scanning systems
摘要： We provide a Biot–Savart inversion scheme that, for any two-dimensional, or bulk with planar crystallization, high-temperature superconducting (HTS) sample, determines current density maps with a higher resolution and accuracy than previous procedures and at a fraction of its computational cost. The starting point of our scheme is a Hall scanning microscopy map of the out-of-plane component of the magnetic field generated by the current. Such maps are noisy in scans of real samples with commercial-grade equipment, and their error is the limiting factor in any Biot–Savart inversion scheme. The main innovation of our proposed scheme is a singular spectrum analysis (SSA) filtering of the Hall probe maps, which cancels measurement errors such as noise or drifts without introducing any artifacts in the field map. The SSA filtering of the Hall probe data is so successful in this task that the resulting magnetic field map does not require an overdetermined QR inversion, allowing Fourier inversion of the Biot–Savart problem. Our implementation of SSA filtering of the Hall scan measurements, followed by Biot–Savart inversion using the fast Fourier transform (FFT), is applied to both simulations and real samples of HTS tape stacks. The algorithm works in cases where ill conditioning ruled out the application of Fourier inversion, and achieves a finer resolution for a fraction of the cost of the QR inversion used to date. The computation passes physical and statistical validity tests in all cases, and in three-dimensional samples it is shown to yield the average, with a depth-dependent weight, of the current density circulating in the different layers of the sample.
关键词： Hall magnetometry,SSA filtering,fast Fourier transform,high-temperature superconducting tapes,Biot–Savart inversion
更新于2025-09-23 15:23:52
-
[IEEE 2018 IEEE International Conference on Signal Processing, Communications and Computing (ICSPCC) - Qingdao, China (2018.9.14-2018.9.16)] 2018 IEEE International Conference on Signal Processing, Communications and Computing (ICSPCC) - A Real-time Detection Algorithm for Unmanned Aerial Vehicle Target in Infrared Search System
摘要： Aiming at the difficulty of infrared target detection of 'low and slow small' unmanned aerial vehicles (UAV) in complex low-altitude background, this paper proposes a new target detection algorithm based on multiscale fusion filtering. Combined with spatial multiscale decomposition filtering and temporal multiscale difference processing, the algorithm can effectively overcome many difficulties such as complex low-altitude background interference, unknown target scale, unknown angular velocity and low target signal-to-noise ratio (SNR). The test result shows that the algorithm can effectively detect the UAV targets with different distances in complex low-altitude background, and the false alarm rate is low. The algorithm is realized in TI 6657 DSP and realizes 100Hz real-time processing of mid-wave infrared images with 640*512 resolution, which has been effectively applied to the large-field circumferential scanning infrared search system developed by ATR Lab.
关键词： real-time algorithm,multiscale fusion filtering,UAV target detection,low-altitude background,low and slow small targets
更新于2025-09-23 15:23:52
-
[IEEE 2018 IEEE 3rd International Conference on Signal and Image Processing (ICSIP) - Shenzhen, China (2018.7.13-2018.7.15)] 2018 IEEE 3rd International Conference on Signal and Image Processing (ICSIP) - Analysis of Linear FM Signal Based on the STFT in the Filtering Viewpoint
摘要： Analyzing signal with STFT transformation is not able to achieve a fine resolution in both the time and frequency due to the restriction of the Heisenberg–Gabor inequality. However, little has been studied about the STFT in the filtering viewpoint, such as the influence of the length of the filter impulse response. This paper mainly studies the frequency estimation of linear frequency modulated (LFM) signal with the STFT in the filtering viewpoint. The length of the filter impulse response is observed in its impact on the variation of time-frequency distribution (TFD). Based on a series of experiments, it is proved that the longer impulse response does not always guarantee the better concentration in the TFD. To obtain the best TFD for the LFM signal processing, an optimal impulse response length needs to be determined beforehand.
关键词： filtering viewpoint,frequency modulation parameters,impulse response
更新于2025-09-23 15:23:52
-
Engineering of carbon-based superlight spin filter with negative differential resistance
摘要： Based on density functional theory and non-equilibrium Green’s function, we investigate the edge hydrogenation and oxidation effects on the spin transport of devices consisting of a zigzag C2N nanoribbon (ZC2NNR) embedded in zigzag graphene nanoribbons in parallel (P) and antiparallel (AP) spin configurations. The results show that device with edge hydrogenation exhibits dual spin filtering effect in AP spin configuration and obvious negative differential resistance in both P and AP spin configuration. By substituting oxygen for hydrogen as passivation atoms of ZC2NNR, the spin filtering efficiency is as high as 100% in the P spin configuration, and the negative differential resistance is largely enhanced with a peak to valley ratio in excess of 4×103. Our theoretical studies suggest that zigzag C2N nanoribbon modulated by edge substitution has great potential in the design of future multifunctional spin devices.
关键词： Negative Differential Resistance,Edge modification,Spin filtering effect,Zigzag C2N nanoribbon
更新于2025-09-23 15:23:52
-
Application of a New Method of Spectral Analysis for Detecting Synchronous Processes in Heliobiology
摘要： Until now, the sum of periodic variations was the main carrier of information in biological and helio-geophysical signals. However, not all of the time series of interest contain dominant periodic components. The relaxation analysis used in this paper makes it possible to generalize the “spectral” formalism to signals that cannot be represented as a sum of a limited number of quasiperiodic components. An algorithm for filtering noise and long-period trends is developed based on the separation of the original signal into rapidly and slowly relaxing components. The main theorem that guarantees the operability of the algorithm is proven. A method for constructing an orthonormal basis whose components have a strictly defined relaxation time is described. The result of the signal expansion over this basis is called the relaxation spectrum. It can be used to divide the time series into signal-to-noise or oscillation-trend if there are no adequate Fourier or stochastic models. The hypothesis that geomagnetic rhythms with periods of about 7 and 9 days have the most significant influence on physiological indicators of biological objects (including those of the population as a whole), as was stated earlier by the heliobiologists, is confirmed based on an automatic algorithm for extracting reliable spectral peaks of population and heliogeomagnetic time series and detecting similar peaks using the S?rensen measure.
关键词： orthonormal basis generation,signal filtering,heliobiophysics,spectral formalism generalization
更新于2025-09-23 15:23:52
-
Microwave Photonic Signal Processing and Sensing Based on Optical Filtering
摘要： Microwave photonics, based on optical filtering techniques, are attractive for wideband signal processing and high-performance sensing applications, since it brings significant benefits to the fields by overcoming inherent limitations in electronic approaches and by providing immunity to electromagnetic interference. Recent developments in optical filtering based microwave photonics techniques are presented in this paper. We present single sideband modulation schemes to eliminate dispersion induced power fading in microwave optical links and to provide high-resolution spectral characterization functions, single passband microwave photonic filters to address the challenges of eliminating the spectral periodicity in microwave photonic signal processors, and review the approaches for high-performance sensing through implementing microwave photonics filters or optoelectronic oscillators to enhance measurement resolution.
关键词： Microwave photonics,photonic filtering,photonic signal processing,single sideband modulation,single passband microwave photonic filter,optical sensors
更新于2025-09-23 15:23:52