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排序方式: 共有233条查询结果,搜索用时 12 毫秒
71.
L-拟序集上的广义Alexandroff拓扑   总被引:1,自引:2,他引:1  
在一类特殊的 L -拟序集上定义广义 Alexandroff拓扑 ,限制到通常的拟序集上就是 Alexandroff拓扑 ,并且该拓扑可以由其上的一族 Alexandroff拓扑取并得到。还证明任意一个拓扑空间的拓扑都可以表示为某个 L-拟序集上的广义 Alexandroff拓扑。  相似文献   
72.

A variant of the classical Koebe-logarithm osculation algorithm for conformal mapping is obtained by inserting a hyperbolic sine at an intermediate step. The modulus of convergence is calculated, and numerical experiments are reported, in particular in comparison with the method of Grassmann [E. Grassmann (1979). Numerical experiments with a method of successive approximation for conformal mapping. J. Applied Mathematics and Physics, 30, 873-884.]. Either procedure may work better, depending upon the domain. Further numerical examples show how the osculation method can be coupled to faster converging algorithms (which tend to work best for nearly-circular domains), thus making feasible computations which would not be accessible by either method alone.  相似文献   
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基于连续逻辑值语义,研究了不分明化sp-拓扑空间,讨论了不分明化的sp-开集,sp-邻域,sp-闭包及sp-内部等性质,给出了不分明化sp-连续映射的概念,引入了范畴FSPTop,证明了范畴FSPTop是范畴Set上的拓扑范畴。  相似文献   
75.
Experiments on a beam-rigid body structure repetitively impacting a rod   总被引:3,自引:0,他引:3  
This paper investigates the experimental dynamics of a beam structure that supports an attached rigid body and that can impact a comparatively compliant base structure. The problem area is motivated by impact phenomena that are observed in certain structures internal to nuclear reactors. The assembly is subjected to base excitation at specified frequency and acceleration, and the resulting displacement and velocity time histories are recorded and used to obtain spectra, phase diagrams, and Poincaré sections. The measurements validate simulation results obtained by using a constraint and modal mapping method based on the two sets of modes when the structure is in-contact, and when it is not-in-contact. Generalized coordinates are mapped across the impact discontinuities in the modal representation. The forced response simulation predicts the test specimen’s response over a range of excitation frequencies. The specimens are fabricated as single integral structures from acrylnitrile butadene styrene plastic through rapid prototyping technology in order to eliminate the undesirable dissipation and flexibility arising from joints and connections. The experimental system can exhibit complex response characteristics, and the influences on complexity of deadband clearance and of asymmetry in the point of impact are examined in the experiments.  相似文献   
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Bent planar waveguides are conformally mapped into straight figures with equivalent index profile. Airy functions of traveling-wave form are introduced to express the radiation mode in the outer cladding region. Calculation results of radiation loss are confirmed to give excellent accuracy.  相似文献   
78.
Module Homomorphisms on Random Normed Modules   总被引:6,自引:0,他引:6  
ModuleHomomorphismsonRandomNormedModulesGuoTiexin(郭铁信)(DepartmentofMathematics,XiamenUniversity,Xiamen,Fujian,361005)Abstract...  相似文献   
79.
扩张原理的一种新的表现形式   总被引:11,自引:7,他引:4  
提出一种基于“模糊点”的模糊集合的分解定理,在此分解定理的基础上给出模糊扩张原理的一种新的表现形式。新的扩张原理与以往人们所提出的扩张原理是等价的,而表现形式更为直观、简便。同时,利用该扩张原理得到模糊复合函数以及多元模糊关系合成运算的合理解释。  相似文献   
80.
We proposed and evaluated an estimation method for the forced selection speech intelligibility tests. Our proposal takes into account the forced selection manner of the Diagnostic Rhyme Test (DRT), which forces selection from a pair of rhyming words. A distance measure is calculated between the test word and the two candidate words, respectively, and the distance is compared to select the most likely word. We compared two distance measures. The first objective distance measure used here was based on the Articulation index Band Correlation (ABC). The ABC is the correlation of time–frequency (T–F) patterns between the test word and the template word speech of the two words in the candidate word pair. The word with the higher correlation was decided to be the likely candidate word. The T–F pattern was calculated in the Articulation Index (AI) bands, and the correlation was calculated between the corresponding bands of the test and candidate word sample. In order to estimate the intelligibility, we calculate the ratio of the number of bands in which higher correlation is seen for the correct word vs. the total number of bands (named ABC-est). This ratio quantifies how well the test word matches the correct word in the word pair. For the second objective distance, we used a measure based on the frequency-weighted segmental SNR (fwSNRseg). Segmental SNR (SNRseg) was calculated in AI bands, and compared among the candidate word templates. We then calculated the frequency-weighted ratio of the number of bands in which higher SNRseg was observed for the correct word vs. the total number of bands (named fwSNRseg-est), again to quantify how well the test word matches the selected candidate word in the pair. We estimated a logistic mapping function from the above two ratios to intelligibility scores using speech mixed with known noise. The mapping functions were then used to estimate the intelligibility of speech mixed with unknown noise. This estimation was compared to another measure that we previously evaluated, the conventional fwSNRseg, which directly maps the measure to intelligibility. Both proposed measures were proven to be significantly more accurate than conventional fwSNRseg. For most cases, the accuracy was comparable between the two proposed distance measures, ABC-est and fwSNRseg-est, with the latter showing correlation between the subjective and estimated intelligibility as high as 0.97, and root mean square as low as 0.11 for one of the test sets, but not as accurate for other sets. The ABC-est showed more stable accuracy for all sets. However, both measures show practical accuracies in all conditions tested. Thus, it should be possible to “screen” the intelligibility in many of the noise conditions to be tested, and cut down on the scale of the subjective test needed.  相似文献   
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