基于信息融合的管道泄漏检测与定位技术应用研究

基于目前已经在石油输送管道中应用的SCADA系统将信息融合技术应用于管道泄漏检测与定位系统中;该方法应用管道泄漏时的多种特征信号,采用最优加权融合算法将多元信息综合处理,扩展了时间和空间上的检测范围,提高了泄漏检测系统的灵敏度和可靠性;在实验室用水泵和不锈钢管道组成的水循环系统进行了模拟实验,通过对比验证了信息融合检漏方法比单一检漏方法具有明显的优越性。     

主体命名方式AST

主体的命名和定位是移动主体中的关键技术,它的优劣影响到整个移动主体系统的性能,在分析了目前几种主体命名和定位方式之后,提出一种新的主体命名和定位的方法：Agent Shadow Tracing。这种方法将主体看成是生成它的主机的一种资源,为主体在生成它的主机上分配一个固定的界面（shadow）,在主体移动时,别的主体和程序可以通过与界面交互达到与移动主体通信的目的,这种方法避免了目前主体命名和定位方式的一些缺点,较好地解决了移动主体之间的通信问题。     

A low cost, non-individualized surround sound system based upon head related transfer functions: an ergonomics study and prototype development

This paper reports on the types and magnitudes of localization errors of simulated binaural direction cues generated using non-individualized, head-related transfer functions (HRTFs) with different levels of complexity. Four levels of complexity, as represented by the number of non-zero coefficients of the associated HRTF filters (128, 64, 32, 18 non-zero coefficients), were studied. Experiment 1 collected 1728 data runs that were exhaustive combinations of the four levels of complexity, nine simulated directions of sound (no direction (i.e., diotical-mono), 0 degrees , 45 degrees , 90 degrees , 135 degrees , 180 degrees , 225 degrees , 270 degrees , and 315 degrees azimuth angles at 0 degrees elevation), two repetitions, and 24 participants). Binaural cues generated from HRTFs of reduced complexity (from 128 to 18 non-zero coefficients) produced significantly higher localization errors for the directions of 45 degrees , 135 degrees , 225 degrees , and 315 degrees azimuth angles (p<0.01). From the directions of 0 degrees , 90 degrees , and 270 degrees azimuth angles, the cues produced by HRTFs with reduced complexity did not affect the localization error (p>0.2). Surprisingly, cues produced by HRTFs of 128 non-zero coefficients did not have the lowest number of errors. From 45 degrees , 135 degrees , 225 degrees , and 315 degrees , the lowest numbers of errors were obtained from cues produced by HRTFs of 64, 32, 32, and 64 non-zero coefficients, respectively. Based on these findings, a prototype virtual headphone-based surround-sound (VHSS) system was developed. A double-blind usability experiment with 32 participants indicated that the prototype VHSS system received significantly better surround-sound ratings than did a Dolby stereo system (p<0.02). This paper reports results from an original ergonomics study and the application of these results to the design of a consumer product.     

Hybrid watermarking of medical images for ROI authentication and recovery

Medical image data require strict security, confidentiality and integrity. To achieve these stringent requirements, we propose a hybrid watermarking method which embeds a robust watermark in the region of non-interest (RONI) for achieving security and confidentiality, while integrity control is achieved by inserting a fragile watermark into the region of the interest (ROI). First the information to be modified in ROI is separated and is inserted into RONI, which later is used in recovery of the original ROI. Secondly, to avoid the underflow and overflow, a location map is generated for embedding the watermark block-wise by leaving the suspected blocks. This avoids the preprocessing step of histogram modification. The image visual quality, as well as tamper localization, is evaluated. We use weighted peak signal to noise ratio for measuring image quality of watermarked images. Experimental results show that the proposed method outperforms the existing hybrid watermarking techniques.     

试析观音信仰在中土嬗变的基本特征

作为佛教体系的重要内容,观音信仰在中土影响之广之深,是其他外来观念形态都难以企及的。然观音信仰如此之地位的获得,源自于其在中土的嬗变;而在这一嬗变的诸特征中,本土化、伦理化、大众化是基本的方面。这"三化"的切实展开,既予观音信仰以中土气息和可亲近感,又使之不冲突佛教基本义理,造就了在中土因成功改化而发展壮大的宗教信仰之典型。     

北本水电项目实施中的人力资源本土化问题研究

北本水电站是我国大唐集团在老挝境内以BOT方式开发建设的第一个大型水电项目。结合北本项目实际,对项目实施人力资源本土化的必要性、制约因素进行了研究分析。根据老挝以及项目实际情况,提出了具体措施和发展设想。     

面向火灾救援的室内定位与逃生路径规划系统

在发生火灾等紧急情况时,由于高层楼宇空间小、出口少的结构特性,受困人员逃生往往很困难。针对传统的被动引导逃生方式中信息获取有限、易产生人群聚集等缺点,该文提出主动式逃生导航的概念,设计了一种改进的K-Means室内定位方法,结合人群密度检测与环境信息采集,进行路径导航,实现了一套基于传感器网络与智能手机的定位导航系统。实验表明,该系统能较好地提高定位精度,避开火灾点,增大每个人的逃生几率,该文为室内逃生导航方案提供了新的思路。     

基于海底磁力仪阵列的磁性目标定位方法

水中磁性目标的探测定位技术具有重要的军事价值。目前利用磁力仪阵列的磁性定位方法需要的采样点多,计算量大,实时性不强。为了更加实时有效地探测水中磁性目标,基于海底磁力仪阵列提出了一个新型磁性目标定位方法,方法包括海底磁力仪阵列的布控和定位计算两方面内容。该方法可以利用磁力仪阵列一组时间点数据实现水中磁性目标的定位计算,具有运算结构简单、实时性强等优点。并通过计算机仿真定量分析了磁力仪精度、磁力仪间隔距离等因素对定位误差的影响。     

基于ZigBee的动态WSN节点定位

针对因障碍物影响而无法实现动态无线传感网MWSN (mobile wireless sensor network)高精度定位的问题,提出了基于RSSI信号传播模型的α-驱动更新的质心定位算法α- drive renewing weighted centroid localization(α-DRWCL).根据WCL (weighted centroid localization)的距离计算公式,建立了路径衰减因子α的计算模型,利用边界探测装置的探测结果适时改变α的值,得到较接近实际情况的各参考节点权重,达到了减小定位误差的目的.在实验环境中对α-DRWCL算法进行定位仿真,仿真结果表明了该算法的精确性和有效性.     

利用国产化技术改造俄制五轴转台控制系统

介绍了俄制五轴转台的基本组成形式和功能,阐述了其存在的故障问题及现状。描述了各个分系统采用的相关控制应用技术和器件实现国产化改造的方案设计内容。并叙述了关键故障问题的原因和解决方案,总结了国产化改造的效益和优点。