基于C30并行多处理器系统的设计与应用

介绍应用于某型声纳仿真测试仪的并行多处理系统，该系统以TMS320C30为基本处理单元，并具有较强的并行处理能力。给出仿真仪的硬件体系结构和软件开发方法，具有性价比高、开发周期短等优点。     

国内客车安全技术研究进展

为提高客车安全性,了解目前客车相关安全标准法规的状况及不足,分析了当前先进的国内汽车主动安全新技术,尤其是部分国内客车企业在安全预警系统、基于ABS的拓展技术及协同式智能安全技术等先进主动安全新技术在客车上的研发和应用;针对国内客车被动安全性存在的问题,分析了部分客车企业在全承载技术、正面碰撞及侧翻试验方面的最新进展状况,并简要概述了国内外安全法规对客车被动安全的性能要求和试验方法。对国内客车安全技术研究进展分析有助于制订更加先进、合理的客车技术标准法规,使其进一步促进国内客车安全技术水平的提高。     

Detecting shifted double JPEG compression tampering utilizing both intra-block and inter-block correlations

Copy-paste forgery is a very common type of forgery in JPEG images.The tampered patch has always suffered from JPEG compression twice with inconsistent block segmentation.This phenomenon in JPEG image forgeries is called the shifted double JPEG(SDJPEG) compression.Detection of SDJPEG compressed image patches can make crucial contribution to detect and locate the tampered region.However,the existing SDJPEG compression tampering detection methods cannot achieve satisfactory results especially when the tampered region is small.In this paper,an effective SDJPEG compression tampering detection method utilizing both intra-block and inter-block correlations is proposed.Statistical artifacts are left by the SDJPEG compression among the magnitudes of JPEG quantized discrete cosine transform(DCT) coefficients.Firstly,difference 2D arrays,which describe the differences between the magnitudes of neighboring JPEG quantized DCT coefficients on the intrablock and inter-block,are used to enhance the SDJPEG compression artifacts.Then,the thresholding technique is used to deal with these difference 2D arrays for reducing computational cost.After that,co-occurrence matrix is used to model these difference 2D arrays so as to take advantage of second-order statistics.All elements of these co-occurrence matrices are served as features for SDJPEG compression tampering detection.Finally,support vector machine(SVM) classifier is employed to distinguish the SDJPEG compressed image patches from the single JPEG compressed image patches using the developed feature set.Experimental results demonstrate the efficiency of the proposed method.     

堤坝检测水下机器人GDROV方案研究

介绍用于查找江、河、湖、海各种堤坝的裂缝、破损和隐患质量等问题的堤坝检测水下机器人的系统组成、基本功能和工作原理,并给出了机械本体、机器人定位系统、堤坝检测系统和控制系统设计方案。     

测深侧扫声纳信号处理中基于相关系数配准方法

对在计算机上计算相关系数的五种常见方法进行了分析,结合测深侧扫声纳信号处理要求提出了最为适合BSSS信号处理运用的相关系数计算方法。用仿真数据进行了检验,结果表明该方法有效。     

谐波治理的研究进展

随着电力电子装置的广泛应用,电力系统的谐波污染日益严重.传统的谐波抑制与无功补偿方法是采用基于谐振原理的无源滤波器,但这样只能滤除设定次数的谐波,且易与电网产生串、并联谐振.而有源滤波器由于具有高度可控性和快速响应性,能对频率和幅值都变化的谐波进行跟踪补偿,因而受到广泛的重视,成为目前国内外供电系统谐波抑制研究的热点.探讨了谐波治理的主要措施,介绍了有源滤波器研究的国内外现状,最后展望了有源滤波器研究的未来方向.     

海漂型浮标干扰设备

对国外常规使用的海漂型声呐探潜浮标特征、参数及工作方式进行了介绍,分析了海漂型声呐探潜浮标干扰机的干扰途径、作用范围及工作原理,并依据最佳性价比的原则给出了一种海漂型浮标干扰设备的原理设计.     

基于能量理论的挡土墙的被动土压力分析

从能量理论出发,导出任意情形下挡土墙被动土压力的计算公式,探讨破裂角的计算方法.与传统的朗金和库伦计算方法相比,该方法应用范围较广,计算结果较为符合实际.     

Underwater sonar image recognition based on gray-spatial histograms

A new gray-spatial histogram is proposed, which incorporates spatial information with gray compositions without sacrificing the robustness of traditional gray histograms. The purpose is to consider the representation role of gray compositions and spatial information simultaneously. Each entry in the gray-spatial histogram is the gray frequency and corresponding position information of images. In the experiments of sonar image recognition, the results show that the gray-spatial histogram is effective in practical use.     

猎雷声纳基阵姿态的稳定与控制

舰壳安装的猎雷声纳需要通过稳定系统隔离舰船的摇摆,以保持姿态的稳定,为发射和接收声纳信号提供稳定的平台.文章介绍了一种用三轴支撑基阵的运动补偿式无平台稳定机构,由导航系统测得的舰船摇摆角经计算,分解到基阵的转动轴上,再分别由伺服系统控制三轴转动,从而消除舰船摇摆的影响,达到稳定基阵姿态的目的.