Article
Chemistry, Analytical
Zhixiong Yang, Kun Li, Chunchao Yu, Mingyao Yuan, Boyang Wang, Jie Feng
Summary: A temporally and spatially modulated long-wave infrared (LWIR)-imaging Fourier transform spectrometer was used to achieve hyperspectral imaging. This method enables rapid detection of hazardous gas leakage, ensuring personal safety.
Article
Mathematics, Applied
Antonio De Martino
Summary: In this paper, we investigate how the short-time Fourier transform can be extended in a Clifford setting, proving some of its main properties and demonstrating the effects of modulating and translating the signal and the window function. Finally, we demonstrate Lieb's uncertainty principle for the Clifford short-time Fourier transform.
APPLIED MATHEMATICS AND COMPUTATION
(2022)
Article
Optics
Zhong Zuo, Chenglin Gu, Daowang Peng, Xing Zou, Yuanfeng Di, Lian Zhou, Daping Luo, Yang Liu, Wenxue Li
Summary: This study successfully demonstrates the generation of a highly mutually coherent dual mid-infrared comb spectrometer based on optical-optical modulation, allowing flexible tuning of center wavelength and parallel detection of multiple molecular species. It shows potential for applications outside the laboratory setting, such as open-path atmospheric gas sensing and industrial process monitoring.
PHOTONICS RESEARCH
(2021)
Article
Mathematics, Applied
Ramanathan Kamalakkannan, Rajakumar Roopkumar, Ahmed Zayed
Summary: In this paper, a short-time coupled fractional Fourier transform (SCFRFT) is introduced using the kernel of the coupled fractional Fourier transform (CFRFT). The authors prove its satisfaction of Parseval's relation, derive its inversion and addition formulas, and characterize its range on L-2(R-2). The study also includes analysis of its time delay and frequency shift properties, and concludes with an uncertainty principle for both the coupled fractional Fourier transform and short-time coupled fractional Fourier transform.
FRACTIONAL CALCULUS AND APPLIED ANALYSIS
(2021)
Article
Engineering, Electrical & Electronic
Gaowa Huang, Feng Zhang, Ran Tao
Summary: The short-time fractional Fourier transform (STFRFT) is a powerful tool for processing signals with fractional frequencies that vary over time. However, the existing discrete algorithms are not suitable for real-time applications that require recalculating the STFRFT at each or several samples. To solve this problem, a new sliding algorithm, called the sliding STFRFT, is proposed. It directly computes the STFRFT at the given time using the output result of the previous time step, significantly reducing computation complexity. The proposed algorithm has been shown to have the lowest computational cost among existing STFRFT algorithms.
IEEE SIGNAL PROCESSING LETTERS
(2022)
Article
Engineering, Electrical & Electronic
Bei Li, Zhuosheng Zhang, Xiangxiang Zhu
Summary: This paper investigates the improved adaptive short-time Fourier transform with chirp-modulated Gaussian window (ASTFT-CMGW) method and proposes a method called ASTFT-CMGW-FVVA with fixed variance and time-frequency-varying parameters. The multitaper ASTFT-CMGW and multitaper extracting transform are developed to further enhance the time-frequency representation precision.
DIGITAL SIGNAL PROCESSING
(2022)
Article
Optics
Shizhu Yuan, Yao Hu, Qun Hao, Shaohui Zhang
Summary: Interferogram demodulation is a fundamental problem in optical interferometry, and obtaining high-accuracy phases from a single-frame interferogram with closed fringes remains challenging. This paper proposes a neural network architecture for single-frame interferogram demodulation, utilizing a specially constructed dataset and training strategy to achieve high-accuracy phase demodulation.
Article
Optics
Zhuoying Wang, Li Xia, Rui Cheng, Guomeng Zuo, Shiyu Li, Zhao Yang
Summary: A novel FOCS demodulation method based on back propagation neural network is proposed to address the challenge of demodulating short-time and weak current signals under ultra-high voltage. The proposed method reduces the impact of background noise and achieves high resolution and accuracy in determining the amplitudes of weak currents. Experimental results demonstrate the reliability and robustness of the method compared to the traditional FFT method.
OPTICS AND LASER TECHNOLOGY
(2022)
Article
Engineering, Electrical & Electronic
Ruichen Liu, Chong Xing, Dongcheng Xie, Yujie Yang, Muhammad Mustafa, Lei Xu, Feng Wu
Summary: This article proposes a SnO2-based low-power quadrilateral gas sensor that achieves different responses through self-temperature modulation using a single-layer electrode. The sensor integrates four detection channels located on the four edges with a quadrilateral microheater. By designing the width of the microheater metal line on the four edges, temperature modulation is achieved to obtain different responses to gases. The sensor shows potential for gas identification and efficient differentiation of food species.
IEEE SENSORS JOURNAL
(2023)
Article
Optics
Firdous A. Shah, Waseem Z. Lone, Azhar Y. Tantary
Summary: The short-time quadratic-phase Fourier transform is introduced to effectively localize the quadratic-phase spectrum of non-transient signals. The preliminary analysis in the quadratic-phase Fourier domain studies the fundamental properties of this transform and formulates various uncertainty inequalities.
Article
Optics
James T. Spollard, Lyle E. Roberts, Callum S. Sambridge, Kirk Mckenzie, Daniel A. Shaddock
Summary: The analysis presents techniques to mitigate the effects of phase noise and Doppler-induced frequency offsets in coherent RAMCW LiDAR, focusing on coherent dual-quadrature detection for a sum of squares calculation. This technique improves SNR for distance measurement and supports measurements of relative radial velocity with unambiguous direction-of-travel, outperforming alternative methods by more than 15 dB.
Article
Chemistry, Analytical
Guangyi Chen, Adam Krzyzak
Summary: In this paper, a novel method for 2D pattern recognition is proposed, which utilizes the log-polar transform, dual-tree complex wavelet transform (DTCWT), and 2D fast Fourier transform (FFT2) to extract features. The new method achieves translation, rotation, and scaling invariance for input 2D pattern images in a multiresolution manner, which is crucial for invariant pattern recognition. Experimental results on a printed Chinese character dataset and a 2D aircraft dataset demonstrate that the new method outperforms two existing methods in most testing cases involving rotations, scaling, and various noise levels in the input pattern images.
Article
Computer Science, Interdisciplinary Applications
Zohre Hoseinzade, Maryam Mokhtari, Kourosh Shirani, Neda Sadat Miresmaeili
Summary: Landslide is a major natural hazard that causes significant damage to humans. This study utilized a frequency-domain format and applied the short-time Fourier transform and weighted overlay methods to detect landslide-prone areas. The results revealed spatial clustering of landslide events in certain regions, providing important insights for landslide prediction and prevention.
EARTH SCIENCE INFORMATICS
(2022)
Article
Optics
Xiuhua Lv, Chenglin Bai, Qi Qi, Hengying Xu, Xueyuan Luo, Xinyu Chi, Lishan Yang, LiXia Xi
Summary: A noise equalization scheme based on complex-valued artificial neural network (c-ANN) is proposed for multiple-eigenvalue modulated NFDM systems. The scheme effectively reduces the impact of noise on the system and demonstrates high performance in long-haul transmission.
Article
Electrochemistry
Anis Allagui, Osama Awadallah, Bilal El-Zahab, Chunlei Wang
Summary: By examining the frequency-domain response of battery signals, the cyclical performance of batteries can be evaluated. In this study, the short-time Fourier transform is used to deconstruct the charge/discharge signals of lithium-sulfur batteries, allowing the detection of critical changes and potential faults.
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
(2023)