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Optoelectronics Letters 2025年第4期21卷 212-217页

作者： JIA Xishan LI Jining YAO Yuan WANG Yifan LIU Bo xu degang School of Precision Instruments and Opto-electronics Engineering Tianjin University Key Laboratory of Optoelectronics Information Technology(Ministry of Education) Tianjin University Institute of Modern Optics College of Electronic Information and Optical Engineering Nankai University Tianjin Key Laboratory of Optoelectronic Sensor and Sensing Network Technology

In this paper, an improved error-rate sliding window decoder is proposed for spatially coupled low-density parity-check(SC-LDPC) codes. For the conventional sliding window decoder, the message retention mechanism causes unreliable messages along the edges of belief propagation(BP) decoding in the current window to be kept for subsequent window decoding.

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A froth velocity measurement method based on improved U-Net++semantic segmentation in flotation process

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International Journal of Minerals,Metallurgy and Materials 2024年第8期31卷 1816-1827页

作者： Yiwei Chen degang xu Kun Wan School of Automation Central South UniversityChangsha 410083China

During flotation,the features of the froth image are highly correlated with the concentrate grade and the corresponding working *** static features such as color and size of the bubbles and the dynamic features such as velocity have obvious differences between different working *** extraction of these features is typically relied on the outcomes of image segmentation at the froth edge,making the segmentation of froth image the basis for studying its visual ***,the absence of scientifically reliable training data with label and the necessity to manually construct dataset and label make the study difficult in the mineral *** solve this problem,this paper constructs a tungsten concentrate froth image dataset,and proposes a data augmentation network based on Conditional Generative Adversarial Nets(cGAN)and a U-Net++-based edge segmentation *** performance of this algorithm is also evaluated and contrasted with other algorithms in this *** the results of semantic segmentation,a phase-correlationbased velocity extraction method is finally suggested.

关键词： froth flotation froth segmentation froth image data augmentation velocity extraction image features

基于DAST晶体的连续太赫兹差频辐射源研究

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物理学报 2025年第3期74卷 118-126页

作者：王泽龙王与烨李海滨张敬喜徐德刚姚建铨天津大学精密仪器与光电子工程学院天津300072 天津大学光电信息技术教育部重点实验室天津300072

基于DAST晶体的太赫兹差频辐射源具有宽调谐、室温运转等优点,但DAST晶体熔点低、热导率低的特性使其在连续泵浦条件下热积累严重、晶体易损伤,这限制了其实际应用.本文理论研究了基于金刚石衬底的DAST晶体的热分布特性,实验分析了金刚... 详细信息

基于DAST晶体的太赫兹差频辐射源具有宽调谐、室温运转等优点,但DAST晶体熔点低、热导率低的特性使其在连续泵浦条件下热积累严重、晶体易损伤,这限制了其实际应用.本文理论研究了基于金刚石衬底的DAST晶体的热分布特性,实验分析了金刚石衬底对DAST晶体中热效应的改善.进一步,基于连续单频激光器与金刚石衬底DAST晶体搭建了差频太赫兹辐射源,其太赫兹波频率调谐范围为1.1—3 THz,在2.493THz处获得最大输出功率为3.39 nW,30 min内太赫兹波的功率不稳定度为2.19%.该窄线宽、可调谐太赫兹辐射源在高精度光谱检测等领域具有较高的应用潜力.

关键词：连续太赫兹源差频产生 DAST晶体

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Effect of phosphogypsum and dicyandiamide as additives on NH_3,N_2O and CH_4 emissions during composting

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Journal of Environmental Sciences 2013年第7期25卷 1338-1345页

作者： Yiming Luo Guoxue Li Wenhai Luo Frank Schuchardt Tao Jiang degang xu College of Resource and Environmental Science China Agricultural University Institute of Agricultural Technology and Biosystems Engineering Johann Heinrich von Thuenen-Institute College of Chemistry Leshan Normal University Research Institute of Safety and Environment Technology CNPC

A laboratory scale experiment of composting in a forced aeration system using pig manure with cornstalks was carried out to investigate the effects of both phosphogypsum and dicyandiamide （DCD, C2 H4 N4 ） as additives on gaseous emissions and compost quality. Besides a control, there were three amended treatments with different amounts of additives. The results indicated that the phosphogypsum addition at the rate of 10% of mixture dry weight decreased NH3 and CH4 emissions significantly during composting. The addition of DCD at the rate of 0.2% of mixture dry weight together with 10% of phosphogypsum further reduced the N20 emission by affecting the nitrification process. Reducing the phosphogypsum addition to 5% in the presence of 0.2% DCD moderately increased the NH3 emissions but not N20 emission. The additives increased the ammonium content and electrical conductivity significantly in the final compost. No adverse effect on organic matter degradation or the germination index of the compost was found in the amended treatments. It was recommended that phosphogypsum and DCD could be used in composting for the purpose of reducing NH3 , CH4 and N20 emissions.0ptimal conditions and dose of DCD additive during composting should be determined with different materials and composting systems in further study.

关键词： composting phosphogypsum dicyandiamide greenhouse gas pig manure

System Architecture Design of PCIe Root Complex Based on SOPC 36

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System Architecture Design of PCIe Root Complex Based on SOP...

Research on Spectral Clustering Algorithms Based on Building Different Affinity Matrix

第36届中国控制会议

作者： Yufeng Liu degang xu Haiming Cai Chunhua Yang College of Information Science and Engineering Central South University

ISBN: (纸本)9781538629185

PCIe bus is widely applied because of its high-bandwidth,high reliability and low cost *** on PCIe root complex architecture based on FPGA begin to receive ***,current methods are usually expensive,code closure and poor flexibility.A new open source PCIe root system architecture based on Xilinx SOPC platform is proposed in this *** system is mainly composed of AXI-PCIe bridge,,AXI interconnect,processing subsystem and DDR3 *** processing system runs the embedded Linux operating system for controlling and management *** AXI-PCIe bridge communicates with the specific PCIe endpoint device and provides the conversion logic for the PCIe domain address and the AXI domain *** are connected by high performance AXI *** paper uses the gigabit ethernet card and network bandwidth testing tools to verify the proposed hardware and software design *** architecture of this approach has the advantages of simple structure,powerful performance and easy expansion,which provides a feasible solution for new high-performance servers and large-scale PLC systems.

关键词： PCIe root complex SOPC processing system AXI-PCIe bridge address translation

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Research on Spectral Clustering Algorithms Based on Building...

Optically pumped terahertz sources

第25届中国控制与决策会议

作者： xu degang Zhao Panlei Gui Weihua Yang Chunhua Xie Yongfang Central South University College of Information Science and Engineering

ISBN: (纸本)9781467355339

As one of the most popular researches in the field of machine learning, spectral clustering algorithms have made great process in many different applications such as image processing. However, there are still some unsolved problems about spectral clustering algorithms, which should be immediately dealt with .These problems include how to build the affinity matrix, and how to deal with the eigenvectors. This paper mainly focuses on building the affinity matrix, which is the most important problem of spectral clustering algorithms. We propose four different methods to build the affinity matrix including the Gaussian kernel function, the Minkowski function, the nearest-correlation function and the local scale function. Then, we develop four new algorithms to contrast the clustering results. Finally, we find that building appropriate local scale function is the most available method to formulate the affinity matrix for spectral clustering algorithm.

关键词： Spectral clustering Gaussian kernel function Minkowski function Nearest-correlation function Local scale function.

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Science China(Technological Sciences) 2017年第12期60卷 1801-1818页

作者： ZHONG Kai SHI Wei xu degang LIU PengXiang WANG YuYe MEI JiaLin YAN Chao FU ShiJie YAO JianQuan Institute of Laser and Optoelectronics College of Precision Instrument and Opto-electronics Engineering Tianjin University Tianjin 300072 China Key Laboratory of Opto-eleetronics Information Technology (Ministry of Education) Tianjin University Tianjin 300072 China

High-power terahertz(THz) generation in the frequency range of 0.1-10 THz has been a fast-developing research area ever since the beginning of the THz boom two decades ago, enabling new technological breakthroughs in spectroscopy, communication, imaging,etc. By using optical(laser) pumping methods with near-or mid-infrared(IR) lasers, flexible and practical THz sources covering the whole THz range can be realized to overcome the shortage of electronic THz sources and now they are playing important roles in THz science and technology. This paper overviews various optically pumped THz sources, including femtosecond laser based ultrafast broadband THz generation, monochromatic widely tunable THz generation, single-mode on-chip THz source from photomixing, and the traditional powerful THz gas lasers. Full descriptions from basic principles to the latest progress are presented and their advantages and disadvantages are discussed as well. It is expected that this review gives a comprehensive reference to researchers in this area and additionally helps newcomers to quickly gain understanding of optically pumped THz sources.

关键词： terahertz(THz) wave photoconductive switch optical rectification difference frequency generation(DFG) terahertz parametric oscillator(TPO) photomixing THz gas lasers phase matching(PM)

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太赫兹参量辐射源研究进展

太赫兹科学与电子信息学报 2025年第2期23卷 73-83页

作者：张敬喜王与烨徐炳烽马鸿儒刘紫鲲徐德刚姚建铨天津大学精密仪器与光电子工程学院天津300072 天津大学光电信息技术教育部重点实验室天津300072

基于受激电磁耦子散射(SPS)的太赫兹参量辐射源是一种光学相干太赫兹辐射源,具有高相干性、频率可调谐、室温运转等优点。本文首先介绍了基于受激电磁耦子散射的基本原理、常用的非线性晶体和耦合技术,重点总结了近年来国内外在增益提... 详细信息

基于受激电磁耦子散射(SPS)的太赫兹参量辐射源是一种光学相干太赫兹辐射源,具有高相干性、频率可调谐、室温运转等优点。本文首先介绍了基于受激电磁耦子散射的基本原理、常用的非线性晶体和耦合技术,重点总结了近年来国内外在增益提升和输出性能提升方面的典型技术与研究成果,以及太赫兹辐射源在物质浓度检测中的应用研究进展,最后分析了太赫兹参量辐射源的关键技术问题以及发展趋势。

关键词：非线性光学太赫兹参量源受激电磁耦子散射非线性晶体

Modeling and Control of Dynamic Network SIR Based on Community Structure

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Modeling and Control of Dynamic Network SIR Based on Communi...

第26届中国控制与决策会议

作者： degang xu Xiyang xu College of Information and Science Technology Central South University

Transmission dynamics has become one hot issue in complex systems and complex networks. It is very urgent to study the influences on the communication process based on the network topology structure. This paper focuses on modeling and control strategy of epidemic transmission SIR（Susceptible-Infected-Recovered） with community structure of networks. Firstly, network community structure features are considered into the classical SIR model by analyzing the characteristic of complex dynamic network. A new modified SIR model with community structure parameters is proposed. The influence of network community structure on epidemic spread is analyzed by numerical simulation. Furthermore, this paper proposes three different control strategies for dynamic network SIR with community structure. These control strategies include random immunization, target immunization strategy and quarantine strategy by different infected parameters and initial value. Numerical simulation shows the validity of our proposed strategies. The research result is very significant for epidemic spreading and control.

关键词： complex network community structure SIR model control strategy

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基于感知特征保持的彩色图像灰度化算法

广东轻工职业技术大学学报 2025年第1期24卷 1-7页

作者：赵孟娟梁义涛史卫亚许德刚李滨夏娟河南工业大学信息科学与工程学院河南郑州450001 河南工业大学人工智能与大数据学院河南郑州450001

彩色图像灰度化是将彩色图像转换为灰度图像的过程,针对现有灰度化算法大多忽略保持图像感知特征的问题,提出一种基于感知特征保持的无参考灰度化深度学习算法。在灰度化网络架构中加入高效多尺度注意力机制EMA(Efficient Multi-Scale A... 详细信息

彩色图像灰度化是将彩色图像转换为灰度图像的过程,针对现有灰度化算法大多忽略保持图像感知特征的问题,提出一种基于感知特征保持的无参考灰度化深度学习算法。在灰度化网络架构中加入高效多尺度注意力机制EMA(Efficient Multi-Scale Attention)增强模型对图像全局和局部特征信息的提取能力;使用感知增强曲线进一步提升了图像的感知特征保留。基于Cadik、CSDD和Kodak三个数据集的实验结果表明,相较于文中提到的五种灰度化方法,本文方法在客观评价指标平均亮度(Absolute Mean Brightness Error,AMBE)和归一化互相关(Normalized Cross-Correlation,NCC)上优势明显,能有效保持图像的对比度、细节和感知等特征。

关键词：灰度化感知保持注意力机制无参考学习