多模态医学图像融合超声检查系统的设计与实现

超声检查系统所呈图像中缺乏三维结构信息,且商业的医学图像分析软件价格昂贵。为此,开发一款综合病灶部位的三维模型和二维超声图像各自特征以及对应空间关系的检查系统。基于开源的医学图像处理软件、商用的电磁定位系统和超声成像系统,在局域网环境下,遵循OpenIGTLink协议进行数据共享的超声检查系统。该系统主要由超声图像信息共享模块、超声图像显示模块、超声探头实时跟踪模块、2D/3D配准融合模块组成。实验结果表明,该系统可初步应用于临床教学和临床辅助诊断等领域,具有价格低廉、扩展性强、维护方便等优势。     

车载PEPS低频自动标定系统

针对车载PEPS系统的低频发射场实测问题,设计了一套汽车电子设备电磁场自动标定系统.该系统控制三维机械臂实现自动行走将场强测试仪送到指定测试点并记录场强值,然后通过可视化技术实现了电磁场强的三维分布显示.设计的标定系统实现了对PEPS系统低频发射场高效而精确的标定,为深入研究PEPS系统电磁场分布特征奠定了基础.     

电磁超声检测钢板厚度实验的参数优化

为提高电磁超声检测信号的信噪比,研究激励信号频率、脉宽及换能器提离距离对厚度测量结果的影响,搭建了电磁超声实验系统。该系统利用RITEC-SNAP 5000产生高能正弦波激励电磁超声换能器EMAT ( Electromagnetic Acoustic Trans-ducer),通过调节激励信号的频率、脉宽,改变提离距离来观测超声回波幅度的变化。实验结果表明：当激励频率和EMAT固有频率相同时其换能效率最高,采用6个周期的脉冲串时前后波包之间分界明显,为获得较大的回波幅度应尽可能减小提离距离。     

Students Weigh In: Usability Test of Online Library Tutorials

Librarians can improve their online tutorials by borrowing usability testing techniques from the computer science field to improve the human-computer interface. This study involved a multimethod usability test of librarian-created tutorials to determine what students learned, how they felt on several affective questions, and what they suggested for improving the tutorials. Results of pre- and post-tests showed that student knowledge increased, and surveys and focus group findings lean to several suggestions for improving engagement and placing tutorials where they will be most effective. This case study demonstrates the value of user input to improve the effectiveness of online instruction for information literacy.     

机载雷达级联降维空时自适应杂波抑制方法

提出一种机载雷达杂波抑制的级联降维空时自适应算法,即,先对全空时两维接收数据进行预滤波处理,将杂波局域化,降低杂波自由度;然后对预处理输出的信号的相关矩阵进行子阵划分,求解低维权向量,进一步降低运算量和采样要求。理论分析和实验仿真结果表明,所提算法具有良好的收敛性能和杂波抑制能力,并且对于阵元随机幅相误差和杂波起伏具有很好的容差能力。基于实测数据的实验验证了算法的有效性和稳健性。     

岩土工程勘察的重点分析

近年来,岩土工程勘察技术发展得非常快,研究领域不断拓展,取得了较多的成就。但是,在发展过程中也存在一些不足。重点分析了岩土工程勘察工作,并结合实际工作提出一些个人意见,以期能为相关工作提供帮助。     

节目传输机房接地系统浅析

根据无线局发射台节目传输机房具有的功能,分析了机房设备安全、人员操作安全和设备稳定运行所需的接地要求,并根据这些要求重点分析了电磁适应接地。     

Query verification schemes for cloud-hosted databases: a brief survey

Database query verification schemes provide correctness guarantees for database queries. Typically such guarantees are required and advisable where queries are executed on untrusted servers. This need to verify query results, even though they may have been executed on one’s own database, is something new that has arisen with the advent of cloud services. The traditional model of hosting one’s own databases on one’s own servers did not require such verification because the hardware and software were both entirely within one’s control, and therefore fully trusted. However, with the economical and technological benefits of cloud services beckoning, many are now considering outsourcing both data and execution of database queries to the cloud, despite obvious risks. This survey paper provides an overview into the field of database query verification and explores the current state of the art in terms of query execution and correctness guarantees provided for query results. We also provide indications towards future work in the area.     

临涣煤矿穿层钻孔水力压裂技术应用研究

针对临涣煤矿存在瓦斯抽采率低、打钻数量过多且瓦斯抽采周期短的问题,提出了采用穿层钻孔实施水力压裂工艺的方法。实验结果表明,临涣煤矿实验区瓦斯标况纯量平均提高了19倍,瓦斯抽采周期延长了3倍多,说明此次井下水力压裂实验基本形成了适用于临涣煤矿矿井的穿层钻孔水力压裂工艺,该煤矿适宜通过水力压裂卸压增透,减少打钻钻孔数量。     

国外武器装备电磁环境适应性试验与评价技术及能力发展综述

武器装备的电磁环境适应性已成为制约武器装备能打仗、打胜仗的一个重大问题;西方军事强国非常重视面向复杂电磁环境的武器装备试验与评价技术研究和能力建设,通过相关投资计划的长期持续投入,支持突破其中的关键技术、方法,以及构建相应的试验与评价设施能力;文章从标准规范和研制程序、技术方法、试验设施、科研和能力建设投资计划等几方面综述了国外武器装备复杂电磁环境适应性试验与评价技术和能力发展情况,并在此基础上,提出了对我国武器装备电磁环境适应性试验与评价能力的发展建议.