Calculation of the Differential Impedance of Tracks on FR4 substrates There is a discrepancy between calculated and measured values of impedance for differential transmission lineson FR4. This is especially noticeable in the case of surface microstrip configurations. The anomaly is shown tobe due to the nature of the substrate material. This needs to be considered as a layered structure of epoxy resinand glass fibre. Calculations, using Boundary Element field methods, show that the distribution of the electricfield within this layered structure determines the apparent dielectric constant and therefore affects theimpedance. Thus FR4 cannot be considered to be uniform dielectric when calculating differential impedance.
上传时间： 2013-10-18
上传用户：masochism
最新的支持向量机工具箱，有了它会很方便 1. Find time to write a proper list of things to do! 2. Documentation. 3. Support Vector Regression. 4. Automated model selection. REFERENCES ========== [1] V.N. Vapnik, "The nature of Statistical Learning Theory", Springer-Verlag, New York, ISBN 0-387-94559-8, 1995. [2] J. C. Platt, "Fast training of support vector machines using sequential minimal optimization", in Advances in Kernel Methods - Support Vector Learning, (Eds) B. Scholkopf, C. Burges, and A. J. Smola, MIT Press, Cambridge, Massachusetts, chapter 12, pp 185-208, 1999. [3] T. Joachims, "Estimating the Generalization Performance of a SVM Efficiently", LS-8 Report 25, Universitat Dortmund, Fachbereich Informatik, 1999.
上传时间： 2013-12-16
上传用户：亚亚娟娟123
A general technique for the recovery of signi cant image features is presented. The technique is based on the mean shift algorithm, a simple nonparametric pro- cedure for estimating density gradients. Drawbacks of the current methods (including robust clustering) are avoided. Feature space of any nature can be processed, and as an example, color image segmentation is dis- cussed. The segmentation is completely autonomous, only its class is chosen by the user. Thus, the same program can produce a high quality edge image, or pro- vide, by extracting all the signi cant colors, a prepro- cessor for content-based query systems. A 512 512 color image is analyzed in less than 10 seconds on a standard workstation. Gray level images are handled as color images having only the lightness coordinate
标签： technique presented features recovery
上传时间： 2015-10-14
上传用户：410805624
Code to run the Non-negative Matrix Factorization algorithm as presented in the Lee, Seung 1999 nature paper.
标签： Factorization Non-negative algorithm presented
上传时间： 2016-01-19
上传用户：litianchu
A stability analysis is presented for staggered schemes for the governing equations of compressible flow. The method is based on Fourier analysis. The approximate nature of pressure-correction solution methods is taken into account. 2001 IMACS. Published by Elsevier Science B.V. All rights reserved
标签： compressible stability for equations
上传时间： 2016-12-02
上传用户：yph853211
We address the problem of predicting a word from previous words in a sample of text. In particular, we discuss n-gram models based on classes of words. We also discuss several statistical algorithms for assigning words to classes based on the frequency of their co-occurrence with other words. We find that we are able to extract classes that have the flavor of either syntactically based groupings or semantically based groupings, depending on the nature of the underlying statistics.
标签： predicting particular previous address
上传时间： 2016-12-26
上传用户：xfbs821
The Kalman filter is a set of mathematical equations that provides an efficient computational [recursive] means to estimate the state of a process, in a way that minimizes the mean of the squared error. The filter is very powerful in several aspects: it supports estimations of past, present, and even future states, and it can do so even when the precise nature of the modeled system is unknown.
标签： computational mathematical equations efficient
上传时间： 2014-06-02
上传用户：yd19890720
9018的管脚图及三极管的测量方法和NPN\PNP的性质和区别Pin diagram of 9018 and the measurement transistor and NPN \ PNP distinction between the nature and
标签： 9018 measurement transistor and
上传时间： 2014-01-01
上传用户：xieguodong1234
This article describes a new efficient implementation of the Cooley-Tukey fast Fourier transform (FFT) algorithm using C++ template metaprogramming. Thank to the recursive nature of the FFT, the source code is more readable and faster than the classical implementation. The efficiency is proved by performance benchmarks on different platforms.
标签： implementation Cooley-Tukey describes efficient
上传时间： 2013-12-23
上传用户：netwolf
A. K. Geim发表在nature上关于异质结的综述文章
标签： heterostructures Waals Van der
上传时间： 2016-05-16
上传用户：xuqiaoling1021
