We analyze, both analytically and numerically, the effectiveness
of cloaking an infinite cylinder from observations by electromagnetic
waves in three dimensions. We show that, as truncated approximations
of the ideal permittivity and permeability tensors tend towards
the singular ideal cloaking fields, so that the anisotropy ratio tends to
infinity, the D and B fields blow up near the cloaking surface. Since
the metamaterials used to implement cloaking are based on effective
medium theory, the resulting large variation in D and B will pose a
challenge to the suitability of the field averaged characterization of "
and 碌. We also consider cloaking with and without the SHS (softand-
hard surface) lining, shown in [6] to be theoretically necessary
for cloaking in the cylindrical geometry. We demonstrate numerically
that cloaking is significantly improved by the SHS lining, with both
the far field of the scattered wave significantly reduced and the blow
up of D and B prevented.
Here are the functions for Hamming code 7.4 and Extended Hamming code 8.4
encoding and decoding.
For 7.4 code, one error per 7-bit codeword can be corrected.
For 8.4 code, one error per 8-bit codeword can be corrected
and not less than 2 errors can be detected.
Study Guide to Accompany Shari Lawrence Pfleeger s
Software Engineering: Theory and Practice
By
Forrest Shull and Roseanne Tesoriero
(very usefull book form student who study Software Engeneering)
進(jìn)程間通信14
說明了進(jìn)程控制原語并且觀察了如何調(diào)用多個(gè)進(jìn)程。但是這些進(jìn)程之間交換信息的
唯一方法是經(jīng)由f o r k或e x e c傳送打開文件，或通過文件系統(tǒng)。本章將說明進(jìn)程之間相互通信的
其他技術(shù)—I P C（InterProcess Communication）。
