基于Linux的无线网络监听技术

为了改善目前无线网络数据监听技术中存在的严重丢包现象,在Linux环境下提出一种基于Libpcap异步机制的监听新方法,可通过进行IEEE 802.11协议的数据包捕获和过滤模块设计,利用Libpcap机制的BPF过滤器和包转发功能,实现无线网络数据包的有效监听。与普通监听技术相比,基于新方法而设计的体系结构丢包少、效率高,能有效提高网络数据监听效率。     

基于BPF的视频课件点播计费系统的研究

首先分析了三种常见的网络流量计费方案的优缺点，然后对BPF的工作原理作了简要的论述，说明其优势所在。对支持BPF的libpcap开发包的 主要组成部分作了简要的叙述，并对各部份的主要函数及其功能作了介绍。最后给出了基于BPF和lipbcap的视频课件流量统计的方法及应用设计框架。     

基于NDIS中间层驱动程序的网络监测器

研究了W indows网络数据包过滤技术和ND IS,设计并实现了W indows 2000平台下基于ND IS中间层驱动程序的网络监测器,它由ND IS IMD包过滤程序和应用层包处理程序2个模块构成,分别负责网络数据包过滤、过滤条件设置与数据包分析处理。该网络监测器适用于W indows 2000平台下IP层及其上层网络协议数据包的过滤和处理。     

基于中间驱动程序的数据包截获技术

为了在防火墙中截获网络封包，并对截获的信息进行处理，本文利用NDIS机制，在DDK环境下进行中间驱动程序的编程，实现了如何通过NDIS对数据包进行截获，进而在此基础上进行加密和过滤等附加操作．     

基于人工神经网络的桩基础选型研究

将人工神经网络引入桩基础选型中，分析影响桩基础选型的重要因素和BP神经网络的特点，确定网络结构。利用Matlab 6．5人工神经网络工具箱构建桩基础选型模型，并利用Matlab语言编制人机交互式界面，使选型过程简单明了。将典型工程项目工程地质资料数据作为网络学习训练样本输入建立的神经网络模型，对其进行训练、优化。经检验。训练好的网络模型性能良好，达到了智能预测的目的。     

基于历史关系模型的时态过滤运算

提出一种新的时态过滤运算，阐述了基于历史关系模型的时态过滤操作，并结合实例予以说明。     

相转移催化法制备含氟环氧树脂的工艺研究

在不同相转移催化剂作用下,六氟双酚A(BPF)和环氧氯丙烷(ECH)缩聚合成含氟双酚A环氧树脂。通过单因素实验确定:在BPF与ECH的摩尔比为1∶10,NaOH的质量分数为30%,反应温度为70℃,反应时间为5 h,四甲基氯化铵的摩尔用量为BPF的1%的条件下,可得到环氧值为0.53的含氟环氧树脂。     

融合图增强和采样策略的图卷积协同过滤模型

现有的基于图卷积网络（GCNs）的协同过滤（CF）模型存在两大问题，大多数原始图因存在噪声及数据稀疏问题会严重损害模型性能；对于大型用户项目图来说，传统GCN中的显式消息传递减慢了训练时的收敛速度，削弱了模型的训练效率.针对上述2点，提出融合图增强和采样策略的图卷积协同过滤模型（EL-GCCF）.图初始化学习模块通过生成2种图结构，综合考虑图中的结构和特征信息，对原始图进行增强，有效缓解了噪声问题.通过多任务的约束图卷积跳过显式的消息传递，利用辅助采样策略有效缓解训练中的过度平滑问题，提高了模型的训练效率.在2个真实数据集上的实验结果表明，EL-GCCF模型的性能优于众多主流模型，并且具有更高的训练效率.     

一种新型网络计费系统的研究

在讨论了网络计费的各项关键技术后，包括网络参数、Linux内核模块、Linux核心过滤模块，提出了1个IP网络宽带计费系统解决方案，并突出介绍了其核心部分IP宽带计费网关的设计与实现．分析了此计费系统的应用前景．     

网络测量及其关键技术

网络测量对网络研究与发展十分重要。分析了网络的常用方法，论述了网络测量的体系结构和研究现状。同时还指出了端到端时延模型、“噪声”分组过滤、测试点最优选择、业务模型分析和时钟偏移影响的消除等网络测量的关键技术。最后说明网络测量在研究网络行为学、网络管理、网络安全和研究网络的新方法、新技术等方面的应用。     

E-51环氧树脂/BPF体系等温固化动力学研究

采用差式扫描量热法(DSC)在等温条件下对E-51/(9,9-双(4-氨基苯基)芴(BPF)环氧树脂体系的固化反应动力学进行了研究.结果表明:该树脂体系的固化反应动力学符合自催化反应动力学模型,应用自催化方程对实验结果进行处理,采用多元非线性最小二乘法进行拟合,得到自催化方程中的所有动力学参数,且活化能为63.75 k...     

紧凑型高共模抑制微带平衡滤波器

针对微带平衡带通滤波器结构不紧凑或共模抑制性能不高等问题,提出了一种高共模抑制的紧凑型微带平衡滤波器.首先给出了平衡滤波器的差模和共模等效电路,分析了交指线耦合谐振单元在差模和共模激励下的工作机理;利用该谐振器对共模信号的失配特性和结构紧凑的特点实现了平衡滤波器的高共模抑制和小型化;最后设计并加工了一款工作于2.45GHz的微带平衡带通滤波器,测试与仿真结果吻合良好.     

Fluxing Agents on Ceramification of Composites of MgO-Al_2O_3-SiO_2/Boron Phenolic Resin

Fluxing agents of zinc borate, antimony oxide, galss frit A and glass frit B, with different melting or softening point temperatures, were added into MgO-Al_2O_3-SiO_2/boron phenol formaldehyde resin(MAS/BPF) composites to lower the formation temperature of eutectic liquid phase and promote the ceramification of ceramifiable composites. The effects of fluxing agents on the thermogravimetric properties, phase evolution, and microstructure evolution of MAS/BPF composites were characterized by TG-DSC, XRD and SEM analyses. The results reveal that the addition of a fluxing agent highly reduces the decomposition rate of MAS/BPF composites. Fluxing agents lower the formation temperatures of liquid phases of ceramifiable MAS/BPF composites obviously, and then promote the ceramification and densification process. The final residues of composites are ceramic surrounded by large amount of glass phases.     

分布式防火墙与入侵检测系统相结合的技术

由于传统防火墙和入侵检测系统的各自不足,在对传统防火墙、入侵检测技术以及数据包过滤器BPF模型分析的基础上,提出了分布式防火墙和入侵检测技术相结合的新的系统设计方案,并对BM字符串匹配算法做了进一步的改进,提高了检测的效率,实现了网络安全的多层防御.     

Fluxing Agents on Ceramification of Composites of MgO-Al<Subscript>2</Subscript>O<Subscript>3</Subscript>-SiO<Subscript>2</Subscript>/Boron Phenolic Resin

Fluxing agents of zinc borate, antimony oxide, galss frit A and glass frit B, with different melting or softening point temperatures, were added into MgO-Al₂O₃-SiO₂/boron phenol formaldehyde resin (MAS/BPF) composites to lower the formation temperature of eutectic liquid phase and promote the ceramification of ceramifiable composites. The effects of fluxing agents on the thermogravimetric properties, phase evolution, and microstructure evolution of MAS / BPF composites were characterized by TG-DSC, XRD and SEM analyses. The results reveal that the addition of a fluxing agent highly reduces the decomposition rate of MAS / BPF composites. Fluxing agents lower the formation temperatures of liquid phases of ceramifiable MAS / BPF composites obviously, and then promote the ceramification and densification process. The final residues of composites are ceramic surrounded by large amount of glass phases.     

平行耦合微带线带通滤波器设计与测试

为了抑制数字通信系统的噪声,利用ADS软件进行建模、优化仿真设计、制造了中心频率为2.4 GHz,带宽120 MHz的平行耦合微带线带通滤波器,并进行了测试,测试的S参数与优化仿真结果、设计指标吻合较好,带内衰减3 dB。在设计过程中同时采用了HFSS仿真设计。本设计的滤波器具有带内插损较小、价格低、易于实现等特点,实际应用效果良好。     

新型微带交叉耦合环微波带通滤波器

设计了一种新型交叉耦合结构带通滤波器,采用了凹槽环形式谐振器,使得获得同样的耦合系数新型结构相邻两环间的距离明显减小,因此这种滤波器具有小型化的优点。通过在传输函数中引入了两个传输零点,使得此种结构的滤波器具有更高的品质因数。利用电磁软件CST的分析给出了此种结构的耦合系数的结构参数,设计了一个工作在X波段的该结构带通滤波器,尺寸为5.9 mm×5.9 mm,带外抑制为25 dB以上,带内插损为3.2 dB,最后的实验结果与仿真曲线一致性较好。     

Ceramification of Composites of MgO-Al_2O_3-SiO_2/Boron Phenolic Resin with Different Calcine Time

The ceramifiable polymer composite of MgO-Al_2O_3-SiO_2/boron phenolic resin(MAS/BPF) with 40wt% of inorganic fillers was calcined at 1 200 ℃ for different time to promote ceramification of ceramifiable composite and improve heat resistance.The effects of different calcine time on the macroscopical morphology,mass loss,phase evolution,microstructure and chemical bond evolution of MAS/BPF composites were characterized by XRD,XPS,and SEM analyses.The experimental results reveal that the increase of calcine time result in the fewer holes,relatively denser and smoother top layer of MAS/BPF composites and protect the interior from deeper decomposition.The final residues of composites are amorphous carbon and C-O-Si-Al-Mg ceramic.And MAS/BPF composites show excellent mass stability,low shrinkage and self-supporting features after 2 h holding compared with BPF composites without 40wt% of inorganic fillers.     

Novel dual-band bandpass filter with wide upper stopband performance

In traditional design of the dual-band bandpass filter (BPF), two or more resonators need to be utilized, which leads to a relatively large circuit size. For miniaturization, a novel stub-loaded square loop quad-mode resonator is proposed in this paper. Due to the symmetry of the structure, the even-odd-mode method is applied twice to analyze its resonance characteristics. All the four mode equivalent circuits are quarter-wavelength resonators, so the resonator has a compact size and the first harmonic is three times the fundamental one. The resonant frequency of each mode can be tuned freely by changing the corresponding physical dimensions, and the passband frequencies and bandwidths of the designed dual-band filter using the proposed resonator are independently controllable. To improve the selectivity and achieve a wide upper stopband, quarter wavelength hook-shape feedlines are designed to provide appropriate external coupling. Two new transmission zeros are generated by the feedlines. Finally, a microstrip dual-band bandpass filter (BPF) centering at 15 and 24GHz with a 3dB fractional bandwidth (FBW) of 107％ and 96％ is designed and fabricated. The measured and simulated results which are in good agreement are presented.