工业CT图像管道拟合

研究了工业CT图像序列中工件内部管道的拟合方法。在利用Facet模型提取管道边缘的基础上,将三维圆柱面、椭圆柱面管道的拟合转化为中心轴截面上的二维轮廓曲线圆、椭圆的拟合,与传统的三维曲面拟合相比,效率更高。通过对实际的发动机工业CT图像进行实验,结果表明该方法可以较准确地获取工件内部管道的几何参数,为基于工业CT的逆向工程打下基础。     

机器人理论关节参数的标定方法及软件设计

本文研究了机器人机构理论控制模型中采用的D-H关节参数的标定方法,并编制了相应的计算机应用软件。应用这一方法和软件标定机器人的理论关节参数,对机器人实施误差综合补偿,提高机器人的精度,是特别重要的。对PUMA 562机器人进行了实测与标定。     

Mapping the 5-50-kDa fraction of human amniotic fluid proteins by 2-DE and ESI-MS

This report presents a proteomic analysis and provides a reference map of the 5-50-kDa components of normal amniotic fluid collected in gestational weeks 16-18. Early amniocentesis samples were pooled and proteins with molecular mass lower than albumin were separated by gel filtration chromatography. The 2-DE protocol was optimized for the separation of the small proteins and peptides in the fraction of interest. A total of 132 Coomassie blue-stained protein spots were analyzed, following in-gel tryptic digestion, by ESI-MS/MS and 49 different gene products were identified. The treatment with alkaline phosphatase caused the shift of the phosphoisoforms of insulin-like growth factor-binding protein-1 and of the N-terminal osteopontin fragment. Of the 33 full-length proteins identified in the 2-DE profile, 23 had not been previously detected in the amniotic fluid and, of these, 22 are not present in the human plasma proteome under physiological conditions. Fragments of 16 larger proteins were identified and the sequence coverage data revealed that several correspond to autonomous domains that may have biological roles on their own. Several of the detected proteins and peptides appear to be involved in critical regulatory processes associated with placentation and early development, thus representing potential markers of various physiological or pathological conditions.     

DDoS下的TCP洪流攻击及对策

分布式拒绝服务攻击(DDoS)是近年来出现的一种极具攻击力的Internet攻击手段,而TCP洪流攻击是其最主要的攻击方式之一。本文提出了一种针对TCP洪流攻击的本地攻击检测-过滤LADF机制,其部署于受害者及其上游ISP网络。该机制综合使用了一种基于信息熵的异常检测技术、SYN-cookie技术和“红名单”技术来检测攻击报文,最终结合新型防火墙技术,构建起一个完善的本地DDoS防御系统。     

环氧树脂掺金属粉末嵌入式FBG封装技术研究

针对光纤光栅(FBG)与被测金属构件可靠连接问题,提出环氧树脂掺金属粉末嵌入式封装技术,阐明了该封装工艺,采用纯弯曲梁对裸光纤光栅和封装后的光纤光栅分别进行应变实验,结果表明,经环氧树脂掺金属粉末封装后的光纤光栅传感器应变灵敏度是裸光纤光栅的1.3倍,达到1.53pm/με,具有很好的重复性,该方法提高了嵌入光纤光栅后被测金属构件的机械强度.     

基于RDF4S语义服务描述模型的服务资源搜索框架

语义服务资源搜索是一个满足服务请求者快速、便捷地定位可用语义服务资源的过程。一个高效、精确的基于语义的语义服务资源搜索框架和经过精心设计并实现的搜索工具是语义服务框架中的一个必要组件。提出一种基于RDF4S语义服务描述模型的服务资源搜索框架,详细说明了该搜索框架的结构。搜索框架根据RDF4S语义服务描述模型的QoS、执行、功能和接口四种语义标注元素类型,分别采用不同的搜索匹配策略,可以很大程度上提高搜索的效率和精度。     

面向过程改进的软件复用能力评估方法

面向复用和基于构件的开发方法已经成为新的软件开发范例，许多企业也已经或计划引入这种新的软件开发方式。与一般的过程能力改进一样，这些企业也面临着如何评估自身当前软件复用能力从而制定下一步改进计划的问题。然而，当前流行的CMM／CMMI以及SPICE等过程标准都缺少面向复用和构件化开发过程的剪裁和定制，这在一定程度上阻碍了软件企业采用新的基于复用的开发方法。本文对软件复用能力评估和改进相关的工业实践和研究情况进行了总结，在此基础上提出了一种系统的软件复用能力评估框架。该框架为企业面向复用的开发过程提供了一种阶段式的评估框架，因此可以为企业面向复用能力的过程改进提供相应的指导和决策依据。本文还对软件复用能力评估框架的实施过程进行了探讨。     

实用软件体系结构研究

该文简要讨论了各种软件体系结构,重点讨论了在实践中如何分析大型MIS系统,如何用软件体系结构的方法来开发软件,并对实践之中出现的问题进行了初步的讨论。     

Efficient DPCA SAR imaging with fast iterative spectrum reconstruction method

The displaced phase center antenna(DPCA)technique is an effective strategy to achieve wide-swath synthetic aperture radar(SAR)imaging with high azimuth resolution.However,traditionally,it requires strict limitation of the pulse repetition frequency(PRF)to avoid non-uniform sampling.Otherwise,any deviation could bring serious ambiguity if the data are directly processed using a matched filter.To break this limitation,a recently proposed spectrum reconstruction method is capable of recovering the true spectrum from the nonuniform samples.However,the performance is sensitive to the selection of the PRF.Sparse regularization based imaging may provide a way to overcome this sensitivity.The existing time-domain method,however,requires a large-scale observation matrix to be built,which brings a high computational cost.In this paper,we propose a frequency domain method,called the iterative spectrum reconstruction method,through integration of the sparse regularization technique with spectrum analysis of the DPCA signal.By approximately expressing the observation in the frequency domain,which is realized via a series of decoupled linear operations,the method performs SAR imaging which is then not directly based on the observation matrix,which reduces the computational cost from O(N2)to O(N log N)(where N is the number of range cells),and is therefore more efficient than the time domain method.The sparse regularization scheme,realized via a fast thresholding iteration,has been adopted in this method,which brings the robustness of the imaging process to the PRF selection.We provide a series of simulations and ground based experiments to demonstrate the high efficiency and robustness of the method.The simulations show that the new method is almost as fast as the traditional mono-channel algorithm,and works well almost independently of the PRF selection.Consequently,the suggested method can be accepted as a practical and efficient wide-swath SAR imaging technique.     

巨磁磁场传感器中噪声研究

巨磁电阻（GMR）材料可应用于弱磁场高灵敏度磁传感器,由于用GMR材料制成的集成化传感器存在较高的巴克豪森噪声,影响了集成化传感器系统的分辨率和稳定性、限制了它的应用。为了控制GMR传感器的巴克豪森噪声,我们从磁性材料、磁性结构及偏磁技术等方面研究了产生巴克豪森噪声的原因,提出了抑制巴克豪森噪声的方法。