期刊文献+
共找到4篇文章
< 1 >
每页显示 20 50 100
星载机械可动天线低频线缆布线 被引量:2
1
作者 徐进 崔华阳 +1 位作者 王浩乐 张阿锋 《空间电子技术》 2018年第1期83-86,110,共5页
星载机械可动天线构型复杂,包含驱动线、热控线、遥测线、接地线等多种类型低频线缆。低频线缆布线设计是影响星载机械可动天线寿命与可靠性的重要因素,也是防勾挂设计的关键。针对布线设计的难点,提出了布线设计准则。三维分级设计提... 星载机械可动天线构型复杂,包含驱动线、热控线、遥测线、接地线等多种类型低频线缆。低频线缆布线设计是影响星载机械可动天线寿命与可靠性的重要因素,也是防勾挂设计的关键。针对布线设计的难点,提出了布线设计准则。三维分级设计提升了布线的科学化、精细化,显著提高了线缆的寿命及可靠性。 展开更多
关键词 星载机械可动天线 低频线缆 布线设计准则 寿命 可靠性
下载PDF
基于Protel99 SE环境下的PCB抗干扰研究 被引量:4
2
作者 赵亚飞 李梦娟 卢进军 《科技信息》 2010年第7期116-117,共2页
为保证电路性能,在进行印制电路板(PCB)设计时应考虑抗干扰性,这对于减小系统电磁信息辐射具有重要的意义。本文着重讨论按元器件的布局及布线原则以最大限度地提高电路的性能指标,达到抗干扰的设计目的。同时也说明了如何通过减小串扰... 为保证电路性能,在进行印制电路板(PCB)设计时应考虑抗干扰性,这对于减小系统电磁信息辐射具有重要的意义。本文着重讨论按元器件的布局及布线原则以最大限度地提高电路的性能指标,达到抗干扰的设计目的。同时也说明了如何通过减小串扰来使电子器件性能最优化。分析了影响PCB抗干扰性能的几个不同因素,说明了PCB制作过程中应采取的解决办法。 展开更多
关键词 PCB设计 串扰 布线准则 器件布局
下载PDF
Characteristics of a bubble jet near a vertical wall
3
作者 张阿漫 姚熊亮 李佳 《Journal of Marine Science and Application》 2008年第1期1-6,共6页
A numerical model of a coupled bubble jet and wall was built on the assumption of potential flow and calculated by the boundary integral method. A three-dimensional computing program was then developed. Starting with ... A numerical model of a coupled bubble jet and wall was built on the assumption of potential flow and calculated by the boundary integral method. A three-dimensional computing program was then developed. Starting with the basic phenomenon of the interaction between a bubble and a wall, the dynamics of bubbles near rigid walls were studied systematically with the program. Calculated results agreed well with experimental results. The relationship between the Bjerknes effect of a wall and characteristic parameters was then studied and the calculated results of various cases were compared and discussed with the Blake criterion based on the Kelvin-impulse theory. Our analyses show that the angle of the jet’s direction and the pressure on the rigid wall have a close relationship with collapse force and the bubble’s characteristic parameters. From this, the application range of Blake criterion can be determined. This paper aims to provide a basis for future research on the dynamics of bubbles near a wall. 展开更多
关键词 bubble jet rigid wall boundary integral Bjerknes effect Blake criterion
下载PDF
Fast uniform content-based satellite image registration using the scale-invariant feature transform descriptor 被引量:3
4
作者 Hamed BOZORGI Ali JAFARI 《Frontiers of Information Technology & Electronic Engineering》 SCIE EI CSCD 2017年第8期1108-1116,共9页
Content-based satellite image registration is a difficult issue in the fields of remote sensing and image processing. The difficulty is more significant in the case of matching multisource remote sensing images which ... Content-based satellite image registration is a difficult issue in the fields of remote sensing and image processing. The difficulty is more significant in the case of matching multisource remote sensing images which suffer from illumination, rotation, and source differences. The scale-invariant feature transform (SIFT) algorithm has been used successfully in satellite image registration problems. Also, many researchers have applied a local SIFT descriptor to improve the image retrieval process. Despite its robustness, this algorithm has some difficulties with the quality and quantity of the extracted local feature points in multisource remote sensing. Furthermore, high dimensionality of the local features extracted by SIFT results in time-consuming computational processes alongside high storage requirements for saving the relevant information, which are important factors in content-based image retrieval (CBIR) applications. In this paper, a novel method is introduced to transform the local SIFT features to global features for multisource remote sensing. The quality and quantity of SIFT local features have been enhanced by applying contrast equalization on images in a pre-processing stage. Considering the local features of each image in the reference database as a separate class, linear discriminant analysis (LDA) is used to transform the local features to global features while reducing di- mensionality of the feature space. This will also significantly reduce the computational time and storage required. Applying the trained kernel on verification data and mapping them showed a successful retrieval rate of 91.67% for test feature points. 展开更多
关键词 Content-based image retrieval Feature point distribution Image registration Linear discriminant analysis REMOTESENSING Scale-invariant feature transform
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部