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2023

Record 25 of

Title:Myocardial Segmentation Algorithm of U-Net Network Based on Cardiac Ultrasound Images

Author(s):Yang, Wang(1,2); Li, Xin(1); Li, Yan(1); Hou, Haoxiong(1,2); Chen, Zuxing(3)
Source: Journal of Physics: Conference Series Volume: 2637 Issue: 1 Article Number: 012049 DOI: 10.1088/1742-6596/2637/1/012049 Published: 2023
Abstract:The myocardial state is always regarded as an important basis for identifying cardiac diseases. In order to assist physicians in diagnosis in an accurate manner, this paper proposes myocardial segmentation using a U-Net network based on cardiac ultrasound images. Firstly, we collected a large amount of clinical data and employed professional cardiac ultrasound imaging physicians to mark the myocardial regions as the gold standard. Then, we built an optimized U-Net network to establish the relationship between images and semantics to extract original image features. Finally, a newly fused loss function for training the network is created. According to the experiments, it shows that the accuracy, precision, and recall rate of U-Net indexes proposed in this paper reaches more than 96%, and MIOU more than 94%, which can effectively assist doctors in diagnosis in an accurate manner. ? Published under licence by IOP Publishing Ltd.
Accession Number: 20235015223203
Record 26 of

Title:Optical Design of the N.A.1.1 Infinite Conjugate Microscopic Objective

Author(s):Guo, Xinran(1); Chen, Weilin(1); Chang, Jun(1); Li, Dongmei(2,3); Chen, Qinfang(4); Li, Chunxin(5)
Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 12595 Issue: null Article Number: 125950Q DOI: 10.1117/12.2667151 Published: 2023
Abstract:In order to solve the serious problem of ordinary biological microscopic objective lenses including field distortion, chromatic aberration and low resolving power, a high-resolution infinite conjugate microscopic objective with three fourth-order Zernike polynomial surfaces has been presented in this paper. The numerical aperture of microscopic system is 1.1 with 2.6mm focal length, which can be equipped with most field lens. The design and analysis results show that the par focal distance of the objective lens is 45mm, and the incidence angle and refraction angle of the optical surface of the lens are less than 60°, which meets the international standard of the microscopic objective lens. The optical modulate transfer function (MTF) curve is close to the theoretical diffraction limit and the RMS wavefront error of the high-performance microscopic objective satisfied Marechal criterion. In addition, the tolerance analysis results show that the system can be processed based on the existing machining methods, despite the wavefront aberration RMS will deteriorate to 0.25λ. The whole system can be used in genetic testing research and mirror test, which is expected to promote the development of medical testing and industrial test and become one of new generation of diagnostic tools. ? 2023 SPIE.
Accession Number: 20232114124201
Record 27 of

Title:Resolution enhancement via guided filtering for spatial-frequency multiplexing single-shot high-speed imaging

Author(s):Li, Hang(1,2,3); Li, Yahui(1,3); Sun, Bonan(4); He, Kai(1,3); Gao, Guilong(1,3); Chen, Ping(1,3); Song, Wenyan(4); Wang, Xing(1,3); Tian, Jinshou(1,3)
Source: Optics Express Volume: 31 Issue: 21 Article Number: null DOI: 10.1364/OE.501678 Published: October 9, 2023
Abstract:The frequency recognition algorithm for multiple exposures (FRAME) is a progressive single-shot high-speed videography technique that employs the spatial-frequency multiplexing concept to provide high temporal and spatial resolution. However, the inherent crosstalk from the zero-frequency component to the carrier-frequency component leads to resolution degradation and artifacts. To improve recovered frames’ quality, we propose a FRAME reconstruction method using guided filters for a removal of the zero-frequency component, which can minimize the artifacts while enhance spatial resolution. A total variation (TV) denoising operation is involved to remove artifacts further to achieve optimized performances. Simulations and experiments were conducted to demonstrate the robust and efficient post-processing capability of the proposed method. With a two-frame experimental system, the results of a USAF 1951 resolution target reveal a 1.8-fold improvement in spatial resolution from 16 lp/mm to 28.5 lp/mm. For complex dynamic scenarios, the wide field of high-speed fuel spray was shot and the proposed method can resolve two droplets with a 30 μm distance which outperforms the traditional method. ? 2023 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement.
Accession Number: 20234314949508
Record 28 of

Title:Surface generation mechanism of the rotary ultrasonic vibration–assisted grinding of aspheric glass ceramics

Author(s):Sun, Guoyan(1,2); Shi, Feng(1); Zhang, Bowen(3); Zhao, Qingliang(3); Zhang, Wanli(1); Wang, Yongjie(2); Tian, Ye(1)
Source: International Journal of Advanced Manufacturing Technology Volume: 124 Issue: 7-8 Article Number: null DOI: 10.1007/s00170-022-10532-5 Published: February 2023
Abstract:A serious challenge faced by manufacturers of large-aperture aspheric optical components of glass ceramics is the long processing time. Ultrasonic vibration–assisted grinding (UVG) allows one to effectively shorten the subsequent polishing process by several times, which is essential for grinding of aspheric components. However, the surface creation mechanism of UVG-treated glass ceramics is rarely studied. Herein, rotary ultrasonic vibration–assisted vertical grinding (RUVG) and parallel grinding (RUPG) are applied to polish the aspheric glass ceramics. Particular attention is paid to the surface formation mechanism of UVG-processed ceramics. The single-grain kinematic functions are created and the contact characteristics between the grinding wheel and aspheric surface are analyzed for the two UVG methods in terms of contact area, velocity, and trajectory. In addition, aspheric grinding texture is simulated and comparative experiments are conducted correspondingly. According to the results, the rotary ultrasonic vibration mainly influences the microscopic grinding marks. Besides, the aspheric surface form accuracy of Pt and RMS value in RUVG is 2.16 and 3.71 times lower than those in RUPG, respectively, whereas the surface roughness–related parameters (mean deviation Sa and maximum height of profile Sz) in RUVG are 6.36% and 4.56% higher than those in RUPG. This indicates that RUVG is more suitable for high precision and efficiency grinding of the aspheric surface than RUPG due to the fact that the polishing depth is primarily determined by surface form accuracy rather than surface roughness. Thus, the current research enables an in-depth understanding of surface generation mechanism in rotary ultrasonic vibration–assisted grinding, pointing out its benefits in the high-efficiency aspheric surface manufacturing. ? 2022, The Author(s), under exclusive licence to Springer-Verlag London Ltd., part of Springer Nature.
Accession Number: 20225113276247
Record 29 of

Title:An efficient lightweight CNN model for real-time fire smoke detection

Author(s):Sun, Bangyong(1); Wang, Yu(1); Wu, Siyuan(2,3)
Source: Journal of Real-Time Image Processing Volume: 20 Issue: 4 Article Number: 74 DOI: 10.1007/s11554-023-01331-6 Published: August 2023
Abstract:Early fire and smoke detection with computer vision have attracted much attention in recent years, and a lot of fire detectors based on deep neural network have been proposed to improve the detection accuracy. However, most current fire detectors still suffer from low detection accuracy caused by the multi-scale variation of the fire and smoke, or the high false accept rate due to the fire-like or smoke-like objects within the background. In this paper, to address the above challenges, we propose an effective real-time fire detection network (AERNet) with two key functional modules, which achieves a good tradeoff between the detection accuracy and speed. First, we employ a lightweight backbone network Squeeze and Excitation-GhostNet (SE-GhostNet) to extract features, which can make it easier to distinguish the fire and smoke from the background and reduce the model parameters greatly. Second, a Multi-Scale Detection module is constructed to selectively emphasize the contribution of different features by channel and space. Finally, we adopt the decoupled head to predict the classes and locations of fire or smoke respectively. In the experiment, we propose a more challenging dataset "Smoke and Fire-dataset" ("SF-dataset") to evaluate the proposed algorithm, which includes 18,217 images. And the results show that the proposed method outperforms most SOTA methods in detection accuracy, model size, and detection speed. ? 2023, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.
Accession Number: 20232514266323
Record 30 of

Title:Silicon-based multi-channel wavelength-division multiplexers for microring optical interconnects

Author(s):Wu, Jinyi(1,2); Xue, Jintao(1,3); Ren, Yangming(1); Wang, Binhao(1,3)
Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 12966 Issue: null Article Number: 129661I DOI: 10.1117/12.3007338 Published: 2023
Abstract:A compact silicon-based four-port coarse wavelength-division multiplexer (CWDM) with a footprint of 200×200 μm2 and an insertion loss of ～2dB is demonstrated. This configuration can support each laser power of over 100mW without inducing silicon nonlinear effects. The design eliminates the need for interference in multiplexing different wavelength channels, resulting in significant fabrication tolerance and eliminating the requirement for phase shifters. The crucial components, such as power splitters/combiners and crossings, are designed and optimized using genetic-algorithm-based deep neural network (GDNN) inverse design methodologies to achieve minimal loss and broad bandwidth. ? COPYRIGHT SPIE. Downloading of the abstract is permitted for personal use only.
Accession Number: 20240115319997
Record 31 of

Title:Reconfigurable Optical Directed Logic Circuits Based on Mode Division Multiplexing Technology

Author(s):Yuan, Mingrui(1); Li, Yiyang(1); Xiao, Huifu(1); Zhou, Xudong(1); Cao, Pengfei(2); Cheng, Lin(2); Ren, Guanghui(3); Hao, Qinfen(4); Xue, Jiuzhi(5,6); Mitchell, Arnan(3); Tian, Yonghui(1,7)
Source: IEEE Photonics Journal Volume: 15 Issue: 3 Article Number: 6601107 DOI: 10.1109/JPHOT.2023.3270341 Published: June 1, 2023
Abstract:Reconfigurable optical directed logic circuits (RODLC) aim to perform arbitrary logic operations using the optical switch network, in which the electrical signals regarded as the logic operands are applied to the optical switch to control the propagation of light over time, and the logic operation results are obtained at the output ports of the optical switch network in the form of light. In this paper, a novel RODLC is proposed and experimentally demonstrated by utilizing an optical switch array with the prosperous optical mode division multiplexing (MDM) technology to perform arbitrary logic functions. As a proof of concept, a RODLC with two optical mode (de)multiplexers and twelve thermo-optic microring resonators on a silicon-on-insulator substrate is fabricated based on standard microfabrication technology. To demonstrate its reconfigurability to perform arbitrary logic functions, eight logic operations: NOT, AND, NAND, OR, NOR, XOR, XNOR, as well as one combination operation of four-operand, with the operation speed of 10 Kbps are successfully implemented as examples. The demonstrated RODLC characterized with reconfigurability, scalability, and ability for large-scale integration, will contribute to the flourishing development of optical computing and information processing in large-scale optical hybrid integrated circuits. ? 2009-2012 IEEE.
Accession Number: 20232114128779
Record 32 of

Title:Spectral Calibration for SO2 Cameras with Light Dilution Effect Correction

Author(s):Wu, Kuijun(1); Guo, Jianjun(1); Zhang, Zihao(1); Zhang, Huiliang(1); Li, Juan(2); Li, Faquan(3); He, Weiwei(1)
Source: Remote Sensing Volume: 15 Issue: 14 Article Number: 3652 DOI: 10.3390/rs15143652 Published: July 2023
Abstract:The detection ability of SO2 cameras has been improved effectively, while the calibration is still the main factor that limits their measurement accuracy. This paper presents a nonlinear calibration theory by considering the effect of light dilution due to the path radiance as well as the dependence of plume aerosol on scattering wavelength. This new spectral calibration method is used to retrieve the SO2 column density and emission rate of the Etna volcano. Results show that, compared with the DOAS calibration approach, the inversion error can be reduced by 13% if the new spectral calibration is adopted. The superiority of the proposed method will become more obvious for long-distance detection of optically thick plumes. ? 2023 by the authors.
Accession Number: 20233114470587
Record 33 of

Title:100-fs time-resolved streak tube design based on anisotropy and post-acceleration technology

Author(s):Tian, Li-Ping(1,3); Shen, Ling-Bin(1,3); Chen, Ping(2); Liu, Yu-Zhu(3); Chen, Lin(1); Hui, Dan-Dan(2); Chen, Xi-Ru(2); Zhao, Wei(2); Xue, Yan-Hua(2); Tian, Jin-Shou(2)
Source: Wuli Xuebao/Acta Physica Sinica Volume: 72 Issue: 24 Article Number: 248502 DOI: 10.7498/aps.72.20231382 Published: December 20, 2023
Abstract:Reducing the space charge effect and the time dispersion caused by the edge field effect of the scanning deflection system is the key to realizing a 100-fs streak tube. In this paper, a novel fs streak tube is proposed and designed. The factors affecting its temporal resolution are analyzed theoretically and the specifications are given. Parameters including the electric field distribution and electron transmittance of the two common acceleration systems (planar cathode-mesh accelerating electrode and planar cathode-slit accelerating electrode) are compared with each other and analyzed theoretically. The results show that although the electric field distribution formed by the planar cathode (mesh accelerating electrode) can form uniform electric field, the electron transmittance is very low; planar cathode-slit accelerating structure will defocus the photoelectron beam along the scanning direction, but the electron transmittance in the effective detection range of the cathode is as high as 100%. The defocusing of the photoelectron beam can be removed by setting a narrow slit in front of the anode. The focusing electrode adopts two sets of plate-like structures which are vertically positioned in front and back to form a one-dimensional focusing electric fields along the scanning direction and the slit direction, respectively. The spatial focusing electrode is arranged close to the phosphor screen, which is beneficial to pushing back the cross-point of the electron beam along the spatial direction. Thus, the electron transit time dispersion in the condition of large electron density will decrease. At the same time, the anode can provide a post-accelerating voltage of +5000 V, which is beneficial to shortening the transit time and dispersion of the photoelectrons, thereby improving the temporal resolution. Based on the above theoretical analysis, a novel femtosecond streak tube is designed by using the planar cathode-slit accelerating electrode, anisotropic focusing system and post-accelerating method. The influence of the anode slit width on the spatial and temporal resolution is simulated. The results show that the temporal resolution deteriorates with the increase of the anode slot width (10-50 μm), due to the fact that the increase of the anode slit width will lead to the gradual increase of the size of the electron spot along the scanning direction, which will lead to the increase of the technical time dispersion. In addition, this study gives the simulation results of the femtosecond streak tube when the anode slit width is in a range of 10-50 μm. The results show that the static spatial resolution is higher than 100 lp/mm at MTF = 10%, dynamic spatial resolution is higher than 29 lp/mm at MTF = 10%, the temporal resolution is better than 122 fs in the range of 4-mm cathode effective detection length. When the effective detection length of the cathode is increased to 8 mm, the dynamic spatial resolution of the streak tube is higher than 22 lp/mm at MTF = 10%, and the temporal resolution is better than 191 fs. ? 2023 Institute of Physics, Chinese Academy of Sciences. All rights reserved.
Accession Number: 20240115318969
Record 34 of

Title:Underwater active polarization descattering based on a single polarized image

Author(s):Li, Haoxiang(1); Zhu, Jingping(1); Deng, Jinxin(1); Guo, Fengqi(1); Zhang, Ning(1,2); Sun, Jian(3); Hou, Xun(1)
Source: Optics Express Volume: 31 Issue: 13 Article Number: null DOI: 10.1364/OE.491900 Published: June 19, 2023
Abstract:Active polarization imaging techniques have tremendous potential for a variety of underwater applications. However, multiple polarization images as input are necessary for almost all methods, thereby limiting the range of applicable scenarios. In this paper, via taking full advantage of the polarization feature of target reflective light, the cross-polarized backscatter image is reconstructed via introducing an exponential function for the first time, only based on mapping relations of co-polarized image. Compared with rotating the polarizer, the result performs a more uniform and continuous distribution of grayscale. Furthermore, the relationship of degree of polarization (DOP) between the whole scene and backscattered light is established. This leads to an accurate estimation of backscattered noise and high-contrast restored images. Besides, single-input greatly simplifies the experimental process and upgrades efficiency. Experimental results demonstrate the advancement of the proposed method for objects with high polarization under various turbidities. ? 2023 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement.
Accession Number: 20232814370464
Record 35 of

Title:Infrared small target segmentation networks: A survey

Author(s):Kou, Renke(1); Wang, Chunping(1); Peng, Zhenming(2); Zhao, Zhihe(3); Chen, Yaohong(4); Han, Jinhui(5); Huang, Fuyu(1); Yu, Ying(1); Fu, Qiang(1)
Source: Pattern Recognition Volume: 143 Issue: null Article Number: 109788 DOI: 10.1016/j.patcog.2023.109788 Published: November 2023
Abstract:Fast and robust small target detection is one of the key technologies in the infrared (IR) search and tracking systems. With the development of deep learning, there are many data-driven IR small target segmentation algorithms, but they have not been extensively surveyed; we believe our proposed survey is the first to systematically survey them. Focusing on IR small target segmentation tasks, we summarized 7 characteristics of IR small targets, 3 feature extraction methods, 8 design strategies, 30 segmentation networks, 8 loss functions, and 13 evaluation indexes. Then, the accuracy, robustness, and computational complexities of 18 segmentation networks on 5 public datasets were compared and analyzed. Finally, we have discussed the existing problems and future trends in the field of IR small target detection. The proposed survey is a valuable reference for both beginners adapting to current trends in IR small target detection and researchers already experienced in this field. ? 2023 Elsevier Ltd
Accession Number: 20232814379128
Record 36 of

Title:Flexible all-optical terahertz switch based on electromagnetically induced transparent-like metamaterial

Author(s):Chen, Run(1,2); Wang, Jiatong(1); Peng, Zhongze(1); Liu, Jiarui(1); Zhang, Min(1,2)
Source: Optical Materials Volume: 145 Issue: null Article Number: 114380 DOI: 10.1016/j.optmat.2023.114380 Published: November 2023
Abstract:The electromagnetically induced transparent-like metamaterials have received much attention because of their excellent slow-light properties and strong nonlinear effects. They have many promising applications in novel terahertz functional devices, high-sensitivity sensors, and optical storages. In this paper, a flexible terahertz switching device based on the electromagnetically induced transparent-like effect was proposed. The device exhibited a significant slow light phenomenon without pumped laser. Meanwhile, it is demonstrated that the device has a large modulation depth and excellent tunable slow light performance with low-power pumped laser. Its amplitude modulation depth can reach 60.4% and the group delay modulation can reach 32.5 ps. And the minimum group velocity of the device in slow terahertz light can reach 0.69 × 105 m/s. Moreover, the flexible substrate of the proposed device is not easily damaged. It makes the device suited for more complex environments well. Therefore, the device will have great potential for future research on high-performance terahertz switching devices. ? 2023 Elsevier B.V.
Accession Number: 20233914811151

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