Yunzuo Zhang^1,*, Shasha Zhang¹, Jiayu Zhang¹, Kaina Guo¹, Zhaoquan Cai²

Intelligent Automation & Soft Computing, Vol.29, No.1, pp. 259-272, 2021, DOI:10.32604/iasc.2021.017200 - 12 May 2021

Abstract Video key frame extraction, reputed as an essential step in video analysis and content-based video retrieval, and meanwhile, also serves as the basis and premise of generating video synopsis. Video key frame extraction means extracting the meaningful parts of the video by analyzing their content and structure to form a concise and semantically expressive summary. Up to now, people have achieved many research results in key frame extraction. Nevertheless, because the surveillance video has no specific structure, such as news, sports games, and other videos, it is not accurate enough to directly extract the key… More >

Amel A. Alaidrous^*

CMC-Computers, Materials & Continua, Vol.67, No.3, pp. 2971-2988, 2021, DOI:10.32604/cmc.2021.015159 - 01 March 2021

Abstract In this paper, we study the water-wave flow under a floating body of an incident wave in a fluid. This model simulates the phenomenon of waves abording a floating ship in a vast ocean. The same model, also simulates the phenomenon of fluid-structure interaction of a large ice sheet in waves. According to this method. We divide the region of the problem into three subregions. Solutions, satisfying the equation in the fluid mass and a part of the boundary conditions in each subregion, are given. We obtain such solutions as infinite series including unknown coefficients.… More >

Dah-Jing Jwo^1,*, Wei-Yeh Chang¹, I-Hua Wu²

CMC-Computers, Materials & Continua, Vol.67, No.3, pp. 3983-4003, 2021, DOI:10.32604/cmc.2021.014752 - 01 March 2021

Abstract This paper revisits the characteristics of windowing techniques with various window functions involved, and successively investigates spectral leakage mitigation utilizing the Welch method. The discrete Fourier transform (DFT) is ubiquitous in digital signal processing (DSP) for the spectrum analysis and can be efficiently realized by the fast Fourier transform (FFT). The sampling signal will result in distortion and thus may cause unpredictable spectral leakage in discrete spectrum when the DFT is employed. Windowing is implemented by multiplying the input signal with a window function and windowing amplitude modulates the input signal so that the spectral… More >

ZHAO JUN^a, LIU AIQIN^a, ZHOU HONG^a, LUO JUN^b,*, AND LIU YUAN^b,*

Journal of Polymer Materials, Vol.37, No.1-2, pp. 29-42, 2020, DOI:10.32381/JPM.2020.37.1-2.3

Abstract Heteroatoms (N, O, and F) and hydrogen groups are important elements for forming the H-bonds. It is well known that a large number of hydrogen groups are formed after curing reaction of epoxy. However, literatures about epoxy resins containing heteroaromatic ring and the H-bonds after cure reaction of the epoxy resins are seldom published. To bridge the gap, a kind of new epoxy monomer containing pyridine ring (EMP) has been synthesized in this work, andit is further cured by 4,4-diaminodiphenyl methane (DDM). The properties of cured EMP/ DDM are evaluated by DSC, DMA, and static More >

Zhenli Wang^{1, *}, Qun Wang¹, Jiayin Liu¹, Zheng Liang¹, Jingsong Xu²

CMC-Computers, Materials & Continua, Vol.65, No.3, pp. 2351-2363, 2020, DOI:10.32604/cmc.2020.011909 - 16 September 2020

Abstract To address the low-resolution imaging problem in relation to traditional Range Doppler (RD) algorithm, this paper intends to propose a new algorithm based on Fractional Fourier Transform (FrFT), which proves highly advantageous in the acquisition of high-resolution Synthetic Aperture Radar (SAR) images. The expression of the optimal order of SAR range signals using FrFT is deduced in detail, and the corresponding expression of the azimuth signal is also given. Theoretical analysis shows that, the optimal order in range (azimuth) direction, which turns out to be very unique, depends on the known imaging parameters of SAR, More >

Zhenli Wang^{1, *}, Qun Wang¹, Fujuan Li¹, Shuai Wang²

CMC-Computers, Materials & Continua, Vol.63, No.3, pp. 1533-1543, 2020, DOI:10.32604/cmc.2020.09721 - 30 April 2020

Abstract The traditional Range Doppler (RD) algorithm is unable to meet practical needs owing to the limit of resolution. The order of fractional Fourier Transform (FrFT) and the length of sampling signals affect SAR imaging performance when FrFT is applied to RD algorithm. To overcome the above shortcomings, the purpose of this paper is to propose a high-resolution SAR image algorithm by using the optimal order of FrFT and the sample length constraints for the range direction. The expression of the optimal order of SAR range signals via FrFT is deduced in detail. The initial sample More >

Oakyoung Han¹, Jaehyoun Kim^{2, *}

CMC-Computers, Materials & Continua, Vol.63, No.2, pp. 553-566, 2020, DOI:10.32604/cmc.2020.09362 - 01 May 2020

Abstract The processing of sound signals is significantly improved recently. Technique for sound signal processing focusing on music beyond speech area is getting attention due to the development of deep learning techniques. This study is for analysis and process of music signals to generate tow-dimensional tabular data and a new music. For analysis and process part, we represented normalized waveforms for each of input data via frequency domain signals. Then we looked into shorted segment to see the difference wave pattern for different singers. Fourier transform is applied to get spectrogram of the music signals. Filterbank… More >

Wei Zhao^{1, 2}, Shuai Feng¹, Yadan Wang¹, Yuanguo Wang¹, Zhihui Han¹, Hu Peng^{1, *}

CMES-Computer Modeling in Engineering & Sciences, Vol.123, No.1, pp. 427-440, 2020, DOI:10.32604/cmes.2020.09387 - 01 April 2020

Abstract Frame rate is an important metric for ultrasound imaging systems, and high frame rates (HFR) benefit moving-target imaging. One common way to obtain HFR imaging is to transmit a plane wave. Delay-and-sum (DAS) beamformer is a conventional beamforming algorithm, which is simple and has been widely implemented in clinical application. Fourier beamforming is an alternative method for HFR imaging and has high levels of imaging efficiency, imaging speed, and good temporal dynamic characteristics. Nevertheless, the resolution and contrast performance of HFR imaging based on DAS or Fourier beamforming are insufficient due to the single plane… More >

Yuan Chen¹, Liangtao Duan¹, Weize Sun^{2, *}, Jingxin Xu³

CMC-Computers, Materials & Continua, Vol.62, No.2, pp. 849-859, 2020, DOI:10.32604/cmc.2020.07115

Abstract In this paper, we address the frequency estimator for 2-dimensional (2-D) complex sinusoids in the presence of white Gaussian noise. With the use of the sinc function model of the discrete Fourier transform (DFT) coefficients on the input data, a fast and accurate frequency estimator is devised, where only the DFT coefficient with the highest magnitude and its four neighbors are required. Variance analysis is also included to investigate the accuracy of the proposed algorithm. Simulation results are conducted to demonstrate the superiority of the developed scheme, in terms of the estimation performance and computational More >

Lizhong Jiang^1,2, Xilin Chai^1,2, Zhihua Tan^1,2, Wangbao Zhou^1,2,*, Yulin Feng^1,2, Zhipeng Lai^1,2, Lan Zheng^1,2

CMES-Computer Modeling in Engineering & Sciences, Vol.121, No.1, pp. 291-314, 2019, DOI:10.32604/cmes.2019.07805

Abstract In order to study the dynamic characteristics of a simply supported double-beam system under a moving mass, the system of fourth-order dynamic partial differential equations of a simply supported double-beam system was transformed into a system of second-order dynamic ordinary differential equations relative to time coordinates by performing the finite sin-Fourier Transform relative to space coordinates. And the analytical solution of the dynamic response of the simply supported double-beam system under a moving mass was obtained by solving the system of dynamic ordinary differential equations. The analytical method and ANSYS numerical method were used to… More >