Research on Sand Dumping Detection of Harbor Dredging Based on Signal Enhancement and Feature Extraction

随着海洋经济发展，各国对港区建设和航道维护愈加重视。但是，在利益驱使下，疏浚驳船常常在非指定区倾倒泥沙，导致航道内泥沙淤积甚至断航，航道维护成本增加和生态坏境破坏。目前，国内普遍采用安装摄像头、吃水线检测等监控方法，但易受人为破坏和环境因素的影响无法获得好的效果。国外采用更改倾倒区和自然处理的手段并不适用于我国流域众多的国情。因此，航道管理部门急需一种非接触式、稳定可靠的监控手段，以保证疏浚工程作业的质量。 本文根据混浊海水声吸收的原理，周期性地发送和接收Chirp探测信号，利用随机共振和时间反转镜技术对接收信号进行增强，并通过希尔伯特-黄变换和稀疏表示的方法提取探测信号成分并获取特征参数，...With the development of Marine economy, the construction of port and waterway maintenance was paid more and more attention to. However, dredging barges always dump illegally due to benefit, which will lead to a silting in the waterway, a huge economic loss and serious damage to ecological environment. The measures taken generally at present, such as installing cameras and water-line detection, are...学位：工程硕士院系专业：信息科学与技术学院_工程硕士(电子与通信工程)学号：2332013115327

OPNET Simulation Method for Underwater Acoustic Networks Based on Chirp Spread Spectrum

针对OPNET软件在水声网络协议仿真中不支持信道结构改变和自定义调制方式的局限,以啁啾扩频的水声网络ALHOA协议仿真为例,提出了一种适合在OPNET上实现更真实水声通信协议仿真的方法。物理层调制方式采用自定义的π/4-DM-DQPSK制式,利用MATLAB将生成的调制曲线导入OPNET中配合OPNET其他管道的配置。在2种具有结构差异的Bellhop信道中验证对ALHOA协议的仿真效果,结果表明信道结构的变化能灵敏地影响ALHOA协议的仿真。此方法对利用OPNET软件灵活开展水声网络协议仿真具有较好的参考价值。Underwater acoustic(UWA) network protocol simulation on OPNET software could not follow the changing of channel structure and did not support custom modulation. In view of the limitations mentioned, a more realistic method of UWA protocol simulation on OPNET was introduced. UWA network ALHOA protocol simulation was token as an example. The physical layer modulation customized was called π/4-DM-DQPSK which was based on Chirp Spread Spectrum. In Matlab, the system would generate a modulation curve which would then be imported into OPNET to adjust the configuration of other pipelines. The simulation results of ALHOA protocol was verified in two Bellhop channels with different structures, which showed changing structure had a sensitive impact on ALHOA protocol. The method introduced has reference value on simulating UWA network protocol flexibly in OPNET.国家自然科学基金项目(61571377;61471308

Application of Chirp Signal in Underwater Acoustic Supervision System for Illegal Throwing Sand Behavior Detection

为找到一种高效便捷的方法判断疏浚船舶是否存在违规抛泥行为,研究了基于啁啾信号探测抛泥行为的方法。设计了3种实现方案:分段FFT(Fast; Fourier Transformation)快速相关、FRFT (Fractional Fourier; Transform)变换、去斜脉冲压缩。结合五缘湾实验及仿真结果验证了3种方案的可行性,同时发现:FRFT变换抗多径和抗噪性能最佳,而去斜脉冲压; 缩算法效果最差。通过分析:当多径影响较为严重时,建议使用FRFT算法进行检测;当多径影响较小而对数据实时性处理要求较高的时,建议使用分段FFT快; 速相关算法进行检测。To find an efficient and convenient method to determine whether a; dredging is illegal is a very meaningful research content. A method of; detection of throwing sand behavior based on Chirp signal was studied; and three implementation schemes (subsection FFT fast correlation), FRFT; and DeChirp were designed. The feasibility of the three schemes was; verified by Wu Yuan Bay experiment and the simulation results.; Anti-multipath and anti-noise performance of FRFT transform is the best.; The performance of dechirp is the worst. Through the analysis, it comes; out the conclusion: when the multipath effect is serious,FRFT algorithm; for detection is recommended; When the multipath effect is small and the; requirement of the data real-time processing is strict,subsection FFT; fast correlation algorithms for detection is recommended.国家自然科学基

基于空间竞争关系的中越边境旅游产品开发研究

本文以广西的友谊关口岸和东兴口岸为例,首先分析了中越地区边境旅游的特点,然后从游客数量、所在区域旅游业发展状况、旅游交通状况、旅游地知名度、区域旅游整体优势等几个角度分别对友谊关口岸和东兴口岸的旅游发展做了一系列对比,为提高该地的旅游竞争力,论文最后从发展目标、旅游通道、产品开发、宣传促销几个方面对其发展提出了建议

注射用盐酸万古霉素胶塞筛选研究

通过考察发现不同供应商、不同材质的胶塞制得的注射用盐酸万古霉素澄清度差异较大。因此，建议本品正式研究前期需对多种胶塞进行筛选，选出对澄清度影响最小的胶塞进行后续处方工艺开发。　</jats:p

Modeling for the sedimentation of dredger and analysis of the influence on sound propagation characteristics

对非刚性水下目标和事件的检测是水下安全警戒的重要内容之一。论文以港口疏浚导致的短时海区内高浓度沙泥侵入为例,探索基于声传感器收发分置的非刚性水下目标检测方法。基于沙泥沉降和声线传播模型,研究非刚性目标在沉降过程中形状、位置变迁对声传播能量及结构的影响规律。计算机仿真与海上实验均表明,局部高浓度泥团在沉降过程中,其形状、密度等指标参数会随时间发生变迁,并对经过其沉降区域的声线能量及结构造成明显影响。通过检测接收声信号能量、结构随沙泥沉降变迁的关系,可实现对水下侵入目标存在性的检测,并为开展进一步的反演、跟踪提供支持,具有一定的研究意义和参考价值。The detection of non-rigid target and event is one of the important content of underwater security.Taking the dredging leads to a short-term high concentration of sand and mud as an example,the non-rigid underwater target detection method based on acoustic sensor transceiver was explored.Based on the sedimentation of sand and mud and the model of acoustic propagation,the law of non-rigid target's shape,location change influence the sound propagation and energy structure were studied.Computer simulation and experiment on the sea both indicated that the shape and density parameters ware changed and while through the dumping area the ray energy and construction were influenced obviously.By detecting the relationship among receiving acoustic signal energy and the structure with the sedimentation of sand and mud can realize the underwater detection of invasion objective,which can provide support for further inversion,tracking and have certain research significance and reference value.国家自然科学基金(61571377,61471308);; 福建省交通运输科技发展项目(201437)资

万山汞矿区弹琴蛙重金属富集与组织关联分析

为了解万山汞矿区弹琴蛙（Nidirana adenopleura）组织重金属富集特征及其关联，对万山汞矿区典型农田生境内弹琴蛙组织（肝脏、皮肤、股骨、肌肉和趾骨）中铬（Cr）、锰（Mn）、镍（Ni）、铜（Cu）、锌（Zn）、镉（Cd）、铅（Pb）、砷（As）、硒（Se）和汞（Hg）这10种重金属元素的生物富集特征差异进行分析，结合非负矩阵分解分析法识别重金属元素的来源及贡献，并通过灰色关联度分析法分析弹琴蛙组织重金属元素间的关联性。结果表明：重金属元素在万山汞矿区弹琴蛙体内富集程度不同，平均质量分数由大到小依次为Zn、Cu、Mn、Pb、Se、Cr、Hg、Cd、Ni、As；Cu、Se、Cr、Ni、Cd和Hg主要富集在肝脏组织中，Mn、Zn和Pb主要富集在股骨和趾骨组织中，As主要富集在肌肉组织中。基于非负矩阵分解和相关分析，Hg、Cu、Cr、Pb和Se主要源于汞矿开采， As主要来源于农业活动，Mn主要来源于锰矿冶炼，Ni、Zn和Cd来源于多种复合途径。总之，两栖动物趾骨具有较好的生物指示作用，可作为一种非致命性的检测方法，用于动物重金属污染的研究。研究结果可为万山汞矿区环境污染防控和野生动物保护提供科学依据

Highly Graphitic Carbon Xerogel as a Stable Support for Proton Exchange Membrane Fuel Cells

Electrocatalyst support, which is used to decrease the usage of platinum and increase the utilization of electrocatalyst, is becoming one of the key materials in PEMFCs. At the same time, its properties directly affect the performance and the durability of fuel cells. In the adverse operating conditions of PEMFCs, such as the acidic environment, the high potential condition and the presence of Pt, Vulcan XC-72 carbon black used as electrocatalyst support can be easily oxidized and degraded