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.
标签： effectiveness analytically numerically cloaking
上传时间： 2017-03-30
上传用户：zxc23456789
GNU Octave is a high-level language, primarily intended for numerical computations. It provides a convenient command line interface for solving linear and nonlinear problems numerically.
标签： computations high-level primarily numerical
上传时间： 2014-01-07
上传用户：星仔
This tutorial was prepared for our freshman engineering students using the student version of MATLAB, because symbolic computations are covered in almost no introductory textbook. We are pleased to make it available to the international community, and would appreciate suggestions for its improvement. MATLAB’s symbolic engine permits the user to do things easily that are difficult or impossible to do numerically
标签： engineering tutorial prepared freshman
上传时间： 2014-01-02
上传用户：lx9076
High-speed Precision numerically Controlled Tapping Using Dual Predictive Control
标签： 神经网络控制
上传时间： 2016-07-20
上传用户：ss183968ss
Regardless of the branch of science or engineering, theoreticians have always been enamored with the notion of expressing their results in the form of closed-form expressions. Quite often, the elegance of the closed-form solution is overshadowed by the complexity of its form and the difficulty in evaluating it numerically. In such instances, one becomes motivated to search instead for a solution that is simple in form and simple to evaluate.
标签： Communication Channels Digital Fading over 1st
上传时间： 2020-05-27
上传用户：shancjb
Regardless of the branch of science or engineering, theoreticians have always been enamored with the notion of expressing their results in the form of closed-form expressions. Quite often the elegance of the closed-form solution is overshadowed by the complexity of its form and the difficulty in evaluating it numerically. In such instances, one becomes motivated to search instead for a solution that is simple in form and likewise simple to evaluate.
标签： Communication Channels Digital Fading over 2nd
上传时间： 2020-05-27
上传用户：shancjb
The basic topic of this book is solving problems from system and control theory using convex optimization. We show that a wide variety of problems arising in system and control theory can be reduced to a handful of standard convex and quasiconvex optimization problems that involve matrix inequalities. For a few special cases there are “analytic solutions” to these problems, but our main point is that they can be solved numerically in all cases. These standard problems can be solved in polynomial- time (by, e.g., the ellipsoid algorithm of Shor, Nemirovskii, and Yudin), and so are tractable, at least in a theoretical sense. Recently developed interior-point methods for these standard problems have been found to be extremely efficient in practice. Therefore, we consider the original problems from system and control theory as solved.
标签： Linear_Matrix_Inequalities_in_Sys tem
上传时间： 2020-06-09
上传用户：shancjb
