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61.
针对雷达目标一维像识别问题,提出了一种基于组织协同进化分类算法的识别方法.该方法与现有进化分类方法的不同之处在于它的进化操作直接作用于样本而不是规则,采用了一种自下而上的搜索机制,即先使若干样本的集合得到进化,再从进化结果中提取规则.这样有利于避免在进化过程中产生无意义的规则.该方法不需要进行特征提取;对于高维数据,不需要预先进行降维处理;没有复杂的运算,训练和识别的速度都很快.对3种飞机微波暗室实测数据的识别实验表明,该方法性能稳定,优于基于支撑矢量机与子波核函数的方法,识别率均达到了96%以上.实验中还对算法的抗噪能力进行了测试,获得了良好的效果. 相似文献
62.
介绍沙角发电C厂2号发电机转子接地检测装置的基本原理和在装置发出报警信号后的分析和判断过程。对该装置出现故障后ALSTOM公司提出的临时检测方案作了分析,指出了该方案的不足之处,提出并实施改进后的临时检测方案。 相似文献
63.
鄂尔多斯盆地姬塬-堡子湾地区长4+5油层成岩作用与储层评价 总被引:4,自引:4,他引:0
利用岩石铸体薄片鉴定、X射线衍射分析、扫描电镜分析等测试手段,对鄂尔多斯盆地姬塬一堡子湾地区延长组长4+5油层储集岩的岩石学特征、成岩作用和物性特征进行了分析。结果表明,该储集岩为细粒的长石砂岩和岩屑长石砂岩,颗粒呈次棱角状,成分成熟度普遍较低,结构成熟度中等一较好;经历了压实、胶结、压溶和溶解等一系列成岩作用;储集岩具有低孔、低渗的特点。在以上研究基础上,结合压汞分析、孔隙组合分析,对储层进行综合评价认为,长4+5储层可分为4类,研究区以Ⅱ、Ⅲ类(中等一差)储层为主。 相似文献
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The object of study is a stationary Gaussian white noise excited multi-degree-of-freedom (MDOF) linear elastic, ideal plastic, linearly damped, statically determinate oscillator with several potential elements of ideal plastic yielding. Specifically the study is exemplified for a plane multistory shear frame with rigid traverses where all the connecting columns except the columns in one or more of the bottom floors have finite symmetrical yield limits. The white noise excitation acts on the mass of the first floor making the movement of the elastic bottom floors simulate a ground motion that interacts with the structure above the bottom floors. The method of study is so-called Slepian model simulation and is in principle the same for other statically determinate MDOF elasto-plastic oscillators of the considered type. The method is fast as compared to direct simulation and provides results that give good insight in the behavior of the plastic displacement response process. 相似文献
68.
Yilmaz Muslu 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1991,51(4):449-460
A dispersed flow model previously developed to study substrate utilization in unsaturated media was experimentally verified and its practical application was considered. For this purpose, measurements were made using tap water and a synthetic feed solution. The importance of the change in fluid regime as regards to the simultaneous transport and reaction within biological filters were demonstrated. The effect of drop formation and the breakage of liquid jets inside the filters on substrate utilization was also shown. 相似文献
69.
Electric dipoles radiate an electromagnetic field into their surroundings. The electric and magnetic fields from a point source or from linear dipoles have components parallel to a spherical surface but also a radial component. In most investigations on radiated fields, only the part of the electric field that is parallel to a spherical surface is taken into account. The argument is that only that component contributes to the radiated energy. Here we show that the phase front in the lower half space is not a spherical surface and hence, the radial components contribute to radiated energy. We show differences in radiation patterns for point electric dipoles and linear dipoles, either modeled as perfectly conducting wires or as resistively loaded wires. Our primary interest lies with improving image resolution through processing of Ground-Penetrating Radar data. Here the emphasis lies with understanding the radiation characteristics of linear dipoles that can be incorporated with image processing algorithms. The model uses a thin-wire approximation for the transmitter antenna. The solution to the discrete system of equations is solved, incorporating interaction between the interface, using a CGFFT scheme including symmetrization and a newly developed preconditioning operator. We look at the electric and magnetic fields as well as the time-averaged Poynting vector radiation patterns in the E-plane and H-plane of the transmitting antenna. The results show that the radial component of the radiated electric and magnetic field is not negligible, even at distances more than seven wavelengths away from the antennas. 相似文献
70.
National and regional corporate spatial structure 总被引:3,自引:0,他引:3
Much is known about the macro-impacts of business activities on national and regional economies; however, comparatively little
is known at the micro level about the impact spatial agglomeration of corporate wealth and performance has on urban systems.
This paper reports on a collaborative research project between the Australian Housing and Urban Research Institute and Dun
and Bradstreet, an international financial credit agency, to analyse the spatial implications of corporate structure in metropolitan
regions. This paper analyses spatial patterns of medium to large businesses in three Australian State capital cities at the
postcode level in order to assess the agglomeration of corporate capital, sales, and performance. The research indicates that
ratio analysis can provide a useful insight into the competitiveness of metropolitan regions and the control corporate headquarters
have over decision making and investment processes. The findings of this research are of special interest to capital markets,
business and urban researchers in the Asia Pacific Region.
Received: September 1997/Accepted: September 2001 相似文献