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基于FPGA的数字视频转换接口的设计与实现

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电子测量技术 2008年第10期31卷 177-179页

作者：罗小巧樊伟良李伟华中师范大学信息技术系武汉430079 湖北中移通信工程责任有限公司武汉430079

本文详细介绍了基于FPGA EP2C35F672的数字视频转换接口的设计及实现方法。重点描述了系统硬件的设计以及FPGA内部逻辑电路的设计,包括串转并、隔行变逐行和颜色空间转换等模块。实现了DVD播放器输出的模拟视频信号通过ADV7181电视解码... 详细信息

本文详细介绍了基于FPGA EP2C35F672的数字视频转换接口的设计及实现方法。重点描述了系统硬件的设计以及FPGA内部逻辑电路的设计,包括串转并、隔行变逐行和颜色空间转换等模块。实现了DVD播放器输出的模拟视频信号通过ADV7181电视解码芯片解码后,在VGA显示器上播放的功能。

关键词：解码器 FPGA 数字视频转换接口 VGA

Bandgap characteristics analysis and graded design of a novel metamaterial for flexural wave suppression

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Applied Mathematics and Mechanics(English Edition) 2025年第1期46卷 1-24页

作者： fan YANG Zhaoyang MA Xingming GUO Shanghai Key Laboratory of Mechanics in Energy Engineering Shanghai Institute of Applied Mathematics and Mechanics School of Mechanics and Engineering ScienceShanghai University Shanghai Institute of Aircraft Mechanics and Control

A novel elastic metamaterial is proposed with the aim of achieving lowfrequency broad bandgaps and bandgap regulation. The band structure of the proposed metamaterial is calculated based on the Floquet-Bloch theorem, and the boundary modes of each bandgap are analyzed to understand the effects of each component of the unit cell on the bandgap formation. It is found that the metamaterials with a low elastic modulus of ligaments can generate flexural wave bandgaps below 300 Hz. Multi-frequency vibrations can be suppressed through the selective manipulation of bandgaps. The dual-graded design of metamaterials that can significantly improve the bandgap width is proposed based on parametric studies. A new way that can regulate the bandgap is revealed by studying the graded elastic modulus in the substrate. The results demonstrate that the nonlinear gradient of the elastic modulus in the substrate offers better bandgap performance. Based on these analyses, the proposed elastic metamaterials can pave the way for multi-frequency vibration control, low-frequency bandgap broadening, and bandgap tuning.

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Dynamic behaviors of graphene platelets-reinforced metal foam piezoelectric beams with velocity feedback control

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Applied Mathematics and Mechanics(English Edition) 2025年第1期46卷 63-80页

作者： Jie CHEN Xinyue ZHANG Mingyang fan School of Mathematics Statistics and Mechanics Beijing University of Technology College of Mechanical & Energy Engineering Beijing University of Technology

Graphene platelets(GPLs)-reinforced metal foam structures enhance the mechanical properties while maintaining the lightweight characteristics of metal foams. Further bonding piezoelectric actuator and sensor layers on the surfaces of GPLs-reinforced metal foam beams enables active vibration control, greatly expanding their applications in the aerospace industry. For the first time, this paper investigates the vibration characteristics and active vibration control of GPLs-reinforced metal foam beams with surfacebonded piezoelectric layers. The constant velocity feedback scheme is used to design the closed-loop controller including piezoelectric actuators and sensors. The effects of the GPLs on the linear and nonlinear free vibrations of the beams are numerically *** Newmark-β method combined with Newton's iteration technique is used to calculate the nonlinear responses of the beams under different load forms including harmonic loads,impact loads, and moving loads. Additionally, special attention is given to the vibration reduction performance of the velocity feedback control on the responses of the beam.

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Optimal binary codes and binary construction of quantum codes

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Frontiers of Computer Science 2014年第6期8卷 1024-1030,1031页

作者： weiliang WANG Yangyu fan Ruihu LI School of Electronics and Information Northwestern Polytechnical University Xi'an 710072 China Science College Air Force Engineering University Xi'an 710051 China

This paper discusses optimal binary codes and pure binary quantum codes created using Steane construction. First, a local search algorithm for a special subclass of quasi-cyclic codes is proposed, then five binary quasi-cyclic codes are built. Second, three classical construction methods are generalized for new codes from old such that they are suitable for constructing binary self-orthogonal codes, and 62 binary codes and six subcode chains of obtained self-orthogonal codes are designed. Third, six pure binary quantum codes are constructed from the code pairs obtained through Steane construction. There are 66 good binary codes that include 12 optimal linear codes, 45 known optimal linear codes, and nine known optimal self-orthogonal codes. The six pure binary quantum codes all achieve the performance of their additive counterparts constructed by quaternary construction and thus are known optimal codes.

关键词： binary linear code binary self-orthogonal code quasi-cyclic code Steane construction quantum code.

基于C++ Builder的RS232串行通信实现

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舰船电子工程 2008年第4期28卷 160-162页

作者：范伟亮杨景曙赵义正合肥解放军电子工程学院电子制约技术重点实验室合肥230037

对Windows环境下,使用C++ Builder编译平台实现RS-232串行通信的方法进行研究,分析比较了三种方法,并例举了在导航系统可视化仿真软件的开发设计中TComm方法的应用。

关键词： C++ Builder RS232 串口通信 PComm Pro

Erf-BP混合像元分解及在森林遥感信息提取中应用

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林业科学 2011年第2期47卷 30-38页

作者：徐小军杜华强周国模董德进范渭亮崔瑞蕊浙江农林大学环境科技学院浙江省森林生态系统碳循环与固碳减排重点实验室临安311300

提出一种新的基于高斯误差函数(Gaussian error function,Erf)作为激活函数的BP神经网络(Erf-BP),并用于林区TM影像进行混合像元分解。研究表明:Erf-BP模型的精度高于线性无约束最小二乘法模型及最大似然法。通过在高分辨率影像上选取... 详细信息

提出一种新的基于高斯误差函数(Gaussian error function,Erf)作为激活函数的BP神经网络(Erf-BP),并用于林区TM影像进行混合像元分解。研究表明:Erf-BP模型的精度高于线性无约束最小二乘法模型及最大似然法。通过在高分辨率影像上选取验证样区精度检验得出:1)各端元总分解精度为89.2%,RMSE比线性无约束最小二乘法模型降低了近39%;2)该方法能够较高精度地提取森林遥感信息,精度达到86%,RMSE比线性无约束最小二乘法模型降低了近40.6%。将3种不同方法估计的整个研究区各端元面积百分比与森林资源二类调查数据作对比得出:Erf-BP模型精度略高于最大似然法,RMSE分别为4.18%和7.90%,两者精度明显高于线性无约束最小二乘法模型(RMSE=18.75%)。Erf-BP算法能够较高精度地对TM影像进行混合像元分解,尤其在森林信息提取上,为基于混合像元分解提取不同森林类型甚至树种遥感信息提供一种可行的方法。

关键词：高斯误差函数误差反向传播算法混合像元分解森林

Optimal slag content for geopolymer composites under freeze-thaw cycles with different freezing temperatures

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2023年第4期24卷 366-376页

作者： Lifeng fan weiliang ZHONG Guang WANG Yan XI Faculty of Architecture Civil and Transportation EngineeringBeijing University of TechnologyBeijing 100124China

Improving the freeze-thaw resistance of geopolymers is of great significance to ensure their durability in cold regions. This study presents an experimental investigation of optimal slag content for geopolymer composites under freeze-thaw cycles with different freezing temperatures. Firstly, five kinds of geopolymer composites with 10.0%, 20.0%, 30.0%, 40.0%,and 50.0% slag contents and 1.0% fiber content were prepared. Freeze-thaw cycle tests at-1.0 ℃,-20.0 ℃, and-40.0 ℃ were carried out for these geopolymer composites and their physical and mechanical properties after the freeze-thaw cycle were tested. The results show that the porosity of the geopolymer composites decreases as the slag content increases. Their mass loss ratio and strength loss ratio increase gradually as the freezing temperature decreases. The mass loss ratio and strength loss ratio of geopolymer composites after freeze-thaw cycles all decrease as the slag content increases. Considering the physical and mechanical properties of geopolymers after freeze-thaw cycles, the optimal slag contents are 40.0% and 50.0%.

关键词： Geopolymer composites Freeze-thaw cycle Freezing temperature Slag content

决策树结合混合像元分解的中国竹林遥感信息提取

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遥感学报 2019年第1期23卷 166-176页

作者：崔璐杜华强周国模李雪建毛方杰徐小军范渭亮李阳光朱迪恩刘腾艳邢璐琪省部共建亚热带森林培育国家重点实验室临安311300 浙江省森林生态系统碳循环与固碳减排重点实验室临安311300 浙江农林大学环境与资源学院临安311300

竹林是中国亚热带地区特殊而重要的森林资源,现有方法难以实现全国范围竹林时空分布信息快速准确提取。针对此问题,本研究利用2003年、2008年、2014年MODIS NDVI、反射率产品数据和省域Landsat分类数据,提出了基于决策树结合混合像元分... 详细信息

竹林是中国亚热带地区特殊而重要的森林资源,现有方法难以实现全国范围竹林时空分布信息快速准确提取。针对此问题,本研究利用2003年、2008年、2014年MODIS NDVI、反射率产品数据和省域Landsat分类数据,提出了基于决策树结合混合像元分解的全国竹林信息提取方法。首先,通过最大似然法获取中国林地分布信息;然后,在林地信息的基础上,构建决策树模型提取中国竹林分布信息;最后,采用线性最小二乘法混合像元分解得到中国竹林丰度图,并计算竹林面积。研究结果表明:(1)最大似然法提取的3个时期中国林地信息的生产者与用户精度均在90%以上,Kappa系数均值为0.93,为竹林信息提取奠定了基础。(2)C5.0算法构建的决策树模型能够很好的提取中国竹林时空分布信息,3个时期竹林分类精度均在80%左右。(3)在混合像元分解的基础上,统计得到的全国各省竹林估算面积与清查面积具有较高的相关性,R^2分别为0.98、0.97和0.95,RMSE范围为3.92万—9.58万ha,说明估算得到全国竹林面积与实际情况较为吻合。本研究所提出基于MODIS遥感数据运用C5.0算法决策树结合混合像元分解的方法,实现了全国竹林时空分布信息的准确提取,为全国竹林资源信息动态监测及管理提供了技术手段和数据支撑。

关键词：中国竹林 MODIS数据 C5.0算法决策树分类混合像元分解

The burden of upper motor neuron involvement is correlated with the bilateral limb involvement interval in patients with amyotrophic lateral sclerosis:a retrospective observational study

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Neural Regeneration Research 2025年第5期20卷 1505-1512页

作者： Jieying Wu Shan Ye Xiangyi Liu Yingsheng Xu Dongsheng fan Department of Neurology Peking University Third HospitalBeijingChina Beijing Municipal Key Laboratory of Biomarker and Translational Research in Neurodegenerative Diseases BeijingChina Key Laboratory for Neuroscience National Health Commission/Ministry of EducationPeking UniversityBeijingChina

Amyotrophic lateral sclerosis is a rare neurodegenerative disease characterized by the involvement of both upper and lower motor *** bilateral limb involvement significantly affects patients'daily lives and may lead them to be confined to ***,the effect of upper and lower motor neuron impairment and other risk factors on bilateral limb involvement is *** address this issue,we retrospectively collected data from 586 amyotrophic lateral sclerosis patients with limb onset diagnosed at Peking University Third Hospital between January 2020 and May 2022.A univariate analysis revealed no significant differences in the time intervals of spread in different directions between individuals with upper motor neuron-dominant amyotrophic lateral sclerosis and those with classic amyotrophic lateral *** used causal directed acyclic graphs for risk factor determination and Cox proportional hazards models to investigate the association between the duration of bilateral limb involvement and clinical baseline characteristics in amyotrophic lateral sclerosis *** factor analyses revealed that higher upper motor neuron scores(hazard ratio[HR]=1.05,95%confidence interval[CI]=1.01–1.09,P=0.018),onset in the left limb(HR=0.72,95%CI=0.58–0.89,P=0.002),and a horizontal pattern of progression(HR=0.46,95%CI=0.37–0.58,P<0.001)were risk factors for a shorter interval until bilateral limb *** results demonstrated that a greater degree of upper motor neuron involvement might cause contralateral limb involvement to progress more quickly in limb-onset amyotrophic lateral sclerosis *** findings may improve the management of amyotrophic lateral sclerosis patients with limb onset and the prediction of patient prognosis.

关键词： amyotrophic lateral sclerosis bilateral limb involvement Cox proportional hazards regression model horizontal spread restricted cubic spline analysis time interval upper motor neuron vertical spread