2024

• Record 37 of
  
  Title:Interaction semantic segmentation network via progressive supervised learning
  
  Author(s):Zhao, Ruini(1); Xie, Meilin(1); Feng, Xubin(1); Guo, Min(1); Su, Xiuqin(1); Zhang, Ping(2)
  Source: Machine Vision and Applications  Volume: 35  Issue: 2  DOI: 10.1007/s00138-023-01500-4  Published: March 2024  
  Abstract:Semantic segmentation requires both low-level details and high-level semantics, without losing too much detail and ensuring the speed of inference. Most existing segmentation approaches leverage low- and high-level features from pre-trained models. We propose an interaction semantic segmentation network via Progressive Supervised Learning (ISSNet). Unlike a simple fusion of two sets of features, we introduce an information interaction module to embed semantics into image details, they jointly guide the response of features in an interactive way. We develop a simple yet effective boundary refinement module to provide refined boundary features for matching corresponding semantic. We introduce a progressive supervised learning strategy throughout the training level to significantly promote network performance, not architecture level. Our proposed ISSNet shows optimal inference time. We perform extensive experiments on four datasets, including Cityscapes, HazeCityscapes, RainCityscapes and CamVid. In addition to performing better in fine weather, proposed ISSNet also performs well on rainy and foggy days. We also conduct ablation study to demonstrate the role of our proposed component. Code is available at: https://github.com/Ruini94/ISSNet © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2024.
  Accession Number: 20241115732788
• Record 38 of
  
  Title:A dual-branch siamese spatial-spectral transformer attention network for Hyperspectral Image Change Detection
  
  Author(s):Zhang, Yiyan(1); Wang, Tingting(1); Zhang, Chenkai(1); Xu, Shufang(1,2); Gao, Hongmin(1); Li, Chenming(1)
  Source: Expert Systems with Applications  Volume: 238  Issue:   DOI: 10.1016/j.eswa.2023.122125  Published: March 15, 2024  
  Abstract:The convolutional neural networks have recently gained widespread attention in Hyperspectral Image Change Detection (HSI-CD) due to their outstanding feature extraction ability. However, limited by the inherent network backbones, the convolutional neural networks (CNNs) fail to mine the sequence attributes and model the intricate relationships of spectral signatures. In contrast, transformers are proficient at learning sequence information owing to the powerful self-attention mechanisms. The two backbone structures exhibit complementary spatial and spectral feature extraction strengths, respectively. Inspired by this, we propose a dual-branch siamese spatial–spectral transformer attention network (DBS3TAN) for HSI-CD. The main idea is to fully exploit the advantages of CNNs and transformers for spatial and spectral feature extraction. More importantly, we devise the two key modules, i.e., the spatial attention module and the spatial–spectral transformer module. The former utilizes depthwise separable convolutions and attention mechanisms to emphasize the features of dual-temporal HSIs from the spatial perspective. The latter focuses on the sequence attributes of spectral signatures and mines the spatial characteristics from adjacent pixels. We employ the weighted contrastive loss function to separate the changed and unchanged pixels more reliably and set the random weight factors to balance the contributions of the two branches. Finally, the threshold values judgment is used to obtain the ultimate detection maps. We conduct extensive experiments to evaluate the DBS3TAN on three HSI datasets, demonstrating its superior performances than compared methods qualitatively and quantitatively. The source code will be available at https://github.com/zhangyiyan001/DBS3TAN. © 2023 Elsevier Ltd
  Accession Number: 20234314969611
• Record 39 of
  
  Title:A Novel Dynamic Contextual Feature Fusion Model for Small Object Detection in Satellite Remote-Sensing Images
  
  Author(s):Yang, Hongbo(1,2); Qiu, Shi(1)
  Source: Information (Switzerland)  Volume: 15  Issue: 4  DOI: 10.3390/info15040230  Published: April 2024  
  Abstract:Ground objects in satellite images pose unique challenges due to their low resolution, small pixel size, lack of texture features, and dense distribution. Detecting small objects in satellite remote-sensing images is a difficult task. We propose a new detector focusing on contextual information and multi-scale feature fusion. Inspired by the notion that surrounding context information can aid in identifying small objects, we propose a lightweight context convolution block based on dilated convolutions and integrate it into the convolutional neural network (CNN). We integrate dynamic convolution blocks during the feature fusion step to enhance the high-level feature upsampling. An attention mechanism is employed to focus on the salient features of objects. We have conducted a series of experiments to validate the effectiveness of our proposed model. Notably, the proposed model achieved a 3.5% mean average precision (mAP) improvement on the satellite object detection dataset. Another feature of our approach is lightweight design. We employ group convolution to reduce the computational cost in the proposed contextual convolution module. Compared to the baseline model, our method reduces the number of parameters by 30%, computational cost by 34%, and an FPS rate close to the baseline model. We also validate the detection results through a series of visualizations. © 2024 by the authors.
  Accession Number: 20241816016150
• Record 40 of
  
  Title:Imaging-based measurement of lunar dust velocity and particle size
  
  Author(s):Dai, YiDan(1,2); Xue, Bin(1); Zhao, YiYi(1); Tao, JinYou(1); Yang, JianFeng(1)
  Source: Applied Optics  Volume: 63  Issue: 9  DOI: 10.1364/AO.516801  Published: February 20, 2024  
  Abstract:This paper introduces an optical–mechanical system designed for the dynamic detection and analysis of lunar dust, typically characterized as particles under 20 micrometers on the lunar surface. The system’s design is both compact and lightweight, aligning with the payload constraints of lunar exploration missions. It is capable of real-time tracking and recording the motion of lunar dust at various altitudes, a crucial capability for understanding the environmental dynamics of the lunar surface. By capturing images and applying sophisticated algorithms, the system accurately measures the velocity and size of dust particles. This approach significantly advances the quantitative analysis of lunar dust, especially during agitation events, filling a critical gap in our current understanding of lunar surface phenomena. The insights gained from this study are not only pivotal for developing theoretical models of lunar surface air flow disturbances and dust movement but also instrumental in designing effective dust mitigation and hazard avoidance strategies for future lunar missions, thereby enhancing both scientific knowledge and the engineering applications in lunar exploration. © 2024 Optica Publishing Group.
  Accession Number: 20241315795715
• Record 41 of
  
  Title:Tracking control of a flexible-link manipulator based on an improved barrier function adaptive sliding mode
  
  Author(s):Jing, Feng(1,2,3); Ma, Caiwen(1,2,3); Wang, Fan(1); Xie, Meilin(1,3); Feng, Xubin(1,3); Fan, Xiao(1,3); Wang, Xuan(1,3); Liu, Peng(1,3)
  Source: Asian Journal of Control  Volume:   Issue:   DOI: 10.1002/asjc.3383  Published: 2024  
  Abstract:In this paper, a novel controller designed for robust tracking control of a flexible-link manipulator operating in the presence of parameter uncertainties and external disturbances within the joint space is introduced. The proposed controller employs an adaptive sliding mode control approach, incorporating an improved barrier function, to ensure that trajectory errors remain within predefined performance bounds. This design enhances the tracking performance without overestimating control-switching gains. Additionally, a fixed-time adaptive sliding mode control, featuring a rapid nonsingular terminal sliding mode variable, is introduced to expedite the convergence rate of the system state during the initial stages. The efficacy of the proposed control scheme is established through the Lyapunov method, demonstrating finite-time convergence of the trajectory error to a specified neighborhood of zero. Experimental validation on a flexible-link system supports the effectiveness and advantages of the proposed control strategy, as evidenced via comparisons with two existing adaptive control schemes. ©2024 Chinese Automatic Control Society and John Wiley & Sons Australia, Ltd.
  Accession Number: 20241715988203
• Record 42 of
  
  Title:Design and optimization of cryogenic installation structure for gratings of Long-wave Infrared Spatial Heterodyne Interferometer
  
  Author(s):Wu, Yang(1,2); Feng, Yutao(1); Han, Bin(1,2); Wu, Junqiang(1); Sun, Jian(1,2)
  Source: Guangxue Jingmi Gongcheng/Optics and Precision Engineering  Volume:   Issue: 2  DOI: 10.37188/OPE.20243202.0171  Published: 2024  
  Abstract:The Long-wave Infrared Spatial Heterodyne Interferometer may have interference fringe distortion due to non-uniform stress acting on the optical components under cryogenic conditions，which will cause performance degradation of the interferometer system. To solve the problem of interference fringe distortion under cryogenic conditions，this paper analyzed the factors affecting interference fringe distortion based on the initial optical mechanical system of Long-wave infrared spatial heterodyne interferometer，and combined the optical-mechanical-thermal coupling analysis method to simulate the cryogenic state of the interferometer system. Then，a cryogenic micro-stress dynamic stable installation structure was designed for grating，which is the key component affecting fringe distortion. After the optimization of structure，the Root-Mean-Square（RMS）and Peak-to-Valley（PV）values of grating’s surface shape are 3. 89×10-2 nm and 2. 21×10-1 nm，respectively，which are five orders of magnitude lower than the initial structure analysis results. The simulated interference fringe distortion is less than 1 detector pixel. The cryogenic verification test of whole system shows that the optimized structure can effectively reduce the distortion of interference fringe，and the distortion is less than 2 detector pixels. The experimental results are highly consistent with the simulation results，which verifies the effectiveness of the optimization analysis method. The optimization analysis method has great significance and value for improving the structural stability and operating performance of the cryogenic reflective optical system. © 2024 Chinese Academy of Sciences. All rights reserved.
  Accession Number: 20240815613472
• Record 43 of
  
  Title:Rapid Determination of Positive–Negative Bacterial Infection Based on Micro-Hyperspectral Technology
  
  Author(s):Du, Jian(1,2); Tao, Chenglong(1,2); Qi, Meijie(1,2); Hu, Bingliang(1,2); Zhang, Zhoufeng(1,2)
  Source: Sensors  Volume: 24  Issue: 2  DOI: 10.3390/s24020507  Published: January 2024  
  Abstract:To meet the demand for rapid bacterial detection in clinical practice, this study proposed a joint determination model based on spectral database matching combined with a deep learning model for the determination of positive–negative bacterial infection in directly smeared urine samples. Based on a dataset of 8124 urine samples, a standard hyperspectral database of common bacteria and impurities was established. This database, combined with an automated single-target extraction, was used to perform spectral matching for single bacterial targets in directly smeared data. To address the multi-scale features and the need for the rapid analysis of directly smeared data, a multi-scale buffered convolutional neural network, MBNet, was introduced, which included three convolutional combination units and four buffer units to extract the spectral features of directly smeared data from different dimensions. The focus was on studying the differences in spectral features between positive and negative bacterial infection, as well as the temporal correlation between positive–negative determination and short-term cultivation. The experimental results demonstrate that the joint determination model achieved an accuracy of 97.29%, a Positive Predictive Value (PPV) of 97.17%, and a Negative Predictive Value (NPV) of 97.60% in the directly smeared urine dataset. This result outperformed the single MBNet model, indicating the effectiveness of the multi-scale buffered architecture for global and large-scale features of directly smeared data, as well as the high sensitivity of spectral database matching for single bacterial targets. The rapid determination solution of the whole process, which combines directly smeared sample preparation, joint determination model, and software analysis integration, can provide a preliminary report of bacterial infection within 10 min, and it is expected to become a powerful supplement to the existing technologies of rapid bacterial detection. © 2024 by the authors.
  Accession Number: 20240515462384
• Record 44 of
  
  Title:Rotating Dual-Retarders to Correct Polarization Measurement Error for Divided-of-Amplitude Polarimeter in Full Field of View
  
  Author(s):Jia, Wentao(1,2); Liu, Kai(1,2); Jiang, Kai(1,2); Shan, Qiusha(1,2); Duan, Jing(1,2); Wu, Linghao(3); Zhou, Liang(1,2)
  Source: SSRN  Volume:   Issue:   DOI: 10.2139/ssrn.4782054  Published: April 2, 2024  
  Abstract:The divided-of-amplitude polarimeter (DoAP) can measure the four Stokes parameters simultaneously, and has the advantages of snapshot and high spatial resolution. However, the residual polarization aberration (PA) of DoPA system will induce the polarization measurement error, and this error is related to the field of view. In this paper, the relationship between the measurement errors of Stokes parameters and the Mueller pupil is derived, and the Mueller pupil of DoPA system is obtained by 3D polarzation ray-tracing matrix. Then, a method of dual-retarders rotation is proposed to correct the Mueller pupil in full field of view. The simulation demonstrates the PA correction can improve the measurement accuracy of DoPA system, and the measurement error of degree of linear polarization is reduced by 11.5%, 38.2% and 11.8% at 0 degree, 10 degrees and 15 degrees field of view, respectively. This research enables high accuracy measurement of polarization signal for polarimeters. © 2024, The Authors. All rights reserved.
  Accession Number: 20240142673
• Record 45 of
  
  Title:Spectral encoder to extract the efficient features of Raman spectra for reliable and precise quantitative analysis
  
  Author(s):Gao, Chi(1,2,3); Fan, Qi(1,2); Zhao, Peng(1,2,3); Sun, Chao(1,2); Dang, Ruochen(1,2,3); Feng, Yutao(1); Hu, Bingliang(1,2); Wang, Quan(1,2)
  Source: Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy  Volume: 312  Issue:   DOI: 10.1016/j.saa.2024.124036  Published: May 5, 2024  
  Abstract:Raman spectroscopy has become a powerful analytical tool highly demanded in many applications such as microorganism sample analysis, food quality control, environmental science, and pharmaceutical analysis, owing to its non-invasiveness, simplicity, rapidity and ease of use. Among them, quantitative research using Raman spectroscopy is a crucial application field of spectral analysis. However, the entire process of quantitative modeling largely relies on the extraction of effective spectral features, particularly for measurements on complex samples or in environments with poor spectral signal quality. In this paper, we propose a method of utilizing a spectral encoder to extract effective spectral features, which can significantly enhance the reliability and precision of quantitative analysis. We built a latent encoded feature regression model; in the process of utilizing the autoencoder for reconstructing the spectrometer output, the latent feature obtained from the intermediate bottleneck layer is extracted. Then, these latent features are fed into a deep regression model for component concentration prediction. Through detailed ablation and comparative experiments, our proposed model demonstrates superior performance to common methods on single-component and multi-component mixture datasets, remarkably improving regression precision while without needing user-selected parameters and eliminating the interference of irrelevant and redundant information. Furthermore, in-depth analysis reveals that latent encoded feature possesses strong nonlinear feature representation capabilities, low computational costs, wide adaptability, and robustness against noise interference. This highlights its effectiveness in spectral regression tasks and indicates its potential in other application fields. Sufficient experimental results show that our proposed method provides a novel and effective feature extraction approach for spectral analysis, which is simple, suitable for various methods, and can meet the measurement needs of different real-world scenarios. © 2024 Elsevier B.V.
  Accession Number: 20240815597901
• Record 46 of
  
  Title:Efficient and high-spatiotemporal-quality terawatt-class mid-infrared optical parametric amplifiers by spatially shaped pumping
  
  Author(s):Liu, Xin(1,2); Li, Jinhui(1,2); Zhen, Qiwen(1,2); Liu, Keyang(1,2); Wang, Yishan(1,2); Zhao, Wei(1,2); Cao, Huabao(1,2); Fu, Yuxi(1,2)
  Source: Journal of the Optical Society of America B: Optical Physics  Volume: 41  Issue: 2  DOI: 10.1364/JOSAB.509609  Published: February 1, 2024  
  Abstract:We propose a method to efficiently generate terawatt (TW)-class mid-infrared (MIR) femtosecond laser pulses with high spatiotemporal quality through optical parametric chirped-pulse amplification (OPCPA). By transforming the pump-beam profile for the OPCPA from Gaussian to flat-top using a designed field mapping optics consisting of two aspherical lenses, we obtain a TW-class femtosecond laser pulse at 2 µm with a conversion efficiency of over 36% according to our simulations. Furthermore, the spatiotemporal coupling effects are greatly suppressed in our method compared to an OPCPA system that is pumped by a widely employed Gaussian profile beam. Our work provides a simple and robust method for developing OPCPA systems with high efficiency and high pulse quality. © 2024 Optica Publishing Group © 2024 Optica Publishing Group (formerly OSA). All rights reserved.
  Accession Number: 20240915655165
• Record 47 of
  
  Title:Design of Optical System for Ultra-Large Range Line-Sweep Spectral Confocal Displacement Sensor
  
  Author(s):Yang, Weiguang(1,2); Du, Jian(1); Qi, Meijie(1); Yan, Jiayue(1,2); Cheng, Mohan(1,2); Zhang, Zhoufeng(1)
  Source: Sensors  Volume: 24  Issue: 3  DOI: 10.3390/s24030723  Published: February 2024  
  Abstract:The spectrum confocal displacement sensor is an innovative type of photoelectric sensor. The non-contact advantages of this method include the capacity to obtain highly accurate measurements without inflicting any harm as well as the ability to determine the object’s surface contour recovery by reconstructing the measurement data. Consequently, it has been widely used in the field of three-dimensional topographic measuring. The spectral confocal displacement sensor consists of a light source, a dispersive objective, and an imaging spectrometer. The scanning mode can be categorized into point scanning and line scanning. Point scanning is inherently present when the scanning efficiency is low, resulting in a slower measurement speed. Further improvements are necessary in the research on the line-scanning type. It is crucial to expand the measurement range of existing studies to overcome the limitations encountered during the detection process. The objective of this study is to overcome the constraints of the existing line-swept spectral confocal displacement sensor’s limited measuring range and lack of theoretical foundation for the entire system. This is accomplished by suggesting an appropriate approach for creating the optical design of the dispersive objective lens in the line-swept spectral confocal displacement sensor. Additionally, prism-grating beam splitting is employed to simulate and analyze the imaging spectrometer’s back end. The combination of a prism and a grating eliminates the spectral line bending that occurs in the imaging spectrometer. The results indicate that a complete optical pathway for the line-scanning spectral confocal displacement sensor has been built, achieving an axial resolution of 0.8 μm, a scanning line length of 24 mm, and a dispersion range of 3.9 mm. This sensor significantly expands the range of measurements and fills a previously unaddressed gap in the field of analyzing the current stage of line-scanning spectral confocal displacement sensors. This is a groundbreaking achievement for both the sensor itself and the field it operates in. The line-scanning spectral confocal displacement sensor’s design addresses a previously unmet need in systematic analysis by successfully obtaining a wide measuring range. This provides systematic theoretical backing for the advancement of the sensor, which has potential applications in the industrial detection of various ranges and complicated objects. © 2024 by the authors.
  Accession Number: 20240715548311
• Record 48 of
  
  Title:Effect of atmospheric environment on the stability of secondary electron emission from magnesium oxide and alumina surfaces
  
  Author(s):Lian, Zhuoxi(1); Zhu, Xiangping(2,3); Wang, Dan(1); Meng, Xiangchen(1); He, Yongning(1)
  Source: Journal of Physics D: Applied Physics  Volume: 57  Issue: 12  DOI: 10.1088/1361-6463/ad15c0  Published: March 22, 2024  
  Abstract:MgO and Al2O3 are two typical ceramics with high secondary electron yield (SEY) and are widely applied in electron multiplier devices as dynode coating. However, dynodes in multipliers are inevitably exposed to various environments, degenerating their SEY performance. To specify the influence of the atmospheric environment on SEY for MgO and Al2O3 ceramics, we conducted environmental stability experiments on MgO and Al2O3 nanofilms. By exposing the nanofilms fabricated by atomic layer deposition to air for certain durations, it was found that although the MgO film possessed high SEY, its SEY decreased significantly as the storage duration increased, specifically, its SEY peak value (δ m) decreased from 5.97 to 3.35 after 180 d. Whereas the SEY of the Al2O3 film changed very little with the storage duration extending, its δ m decreased from 4.01 to 3.70 after 180 d, indicating the Al2O3 film had good SEY environmental stability. To reveal the mechanism of SEY degradation, the modification analysis of surface composition was implemented. It was found that the surface of MgO film underwent degradation besides unavoidable contamination, generating Mg(OH)2 and MgCO3. Whereas, there is no chemical reaction occurred on the Al2O3 surface. Combining the advantages of high SEY of MgO and good environmental stability of Al2O3, several Al2O3/MgO double-layer nanofilms were prepared. The δ m value of 20 nm MgO nanofilms covered by 1 nm Al2O3, decreased from 4.90 to 4.56, with a reduction of only 6.94% after 180 d. The results showed that the Al2O3 film achieved effective protection of the MgO film. The SEY environmental stability of the double-layer structure was significantly improved, and the effect of thickness on SEY was theoretically interpreted. This work makes significant sense for understanding the influence of the environment on the SEY for MgO and Al2O3, which has potential applications in electron multipliers. © 2023 IOP Publishing Ltd.
  Accession Number: 20240115304780