Analysis of upsets and failures due to ESD by the FDTD-INBCs method

In this paper, a finite-difference time-domain (FDTD) model of an electrostatic discharge (ESD) event is developed. Analytical expressions for the field radiated during the ESD discharge phase have been determined to test the FDTD model of the strike arc. In order to take into account the electromagnetic field penetration through shielding structures, the conductive panels are efficiently modeled in the FDTD by the impedance network boundary conditions (INBCs). The FDTD-INBCs method avoids the huge amount of cells needed to model accurately the penetration in the traditional FDTD algorithm based on the utilization of the regular Yee grid. The method is applied to the analysis of ESD events in some configurations

A sequential algorithm for training the SOM prototypes based on higher-order recursive equations

A novel training algorithm is proposed for the formation of Self-Organizing Maps (SOM). In the proposed model, the weights are updated incrementally by using a higher-order difference equation, which implements a low-pass digital filter. It is possible to improve selected features of the self-organization process with respect to the basic SOM by suitably designing the filter. Moreover, from this model, new visualization tools can be derived for cluster visualization and for monitoring the quality of the map

On the ergodic decomposition for a cocycle

International audienceLet (X, {\goth X}, \mu, \tau) be an ergodic dynamical system and $\varphi$ be a measurable map from $X$ to a locally compact second countable group $G$ with left Haar measure $m_G$. We consider the map $\tau_\varphi$ defined on $X \times G$ by $\tau_\varphi: (x,g) \rightarrow (\tau x, \varphi(x)g)$ and the cocycle $(\varphi_n)_{n \in \mathbb{Z}}$ generated by $\varphi$. Using a characterization of the ergodic invariant measures for $\tau_\varphi$ (\cite{Ra06}), we give the form of the ergodic decomposition of $\mu(dx) \otimes m_G(dg)$ or more generally of the $\tau_\varphi$-invariant measures $\mu_\chi(dx) \otimes \chi(g) m_G(dg)$, where $\mu_\chi(dx)$ is $\chi\circ \varphi$-conformal for an exponential $\chi$ on $G$

An evolutionary algorithm for global optimization based on self-organizing maps

In this article, a new population-based algorithm for real-parameter global optimization is presented, which is denoted as self-organizing centroids optimization (SOC-opt). The proposed method uses a stochastic approach which is based on the sequential learning paradigm for self-organizing maps (SOMs). A modified version of the SOM is proposed where each cell contains an individual, which performs a search for a locally optimal solution and it is affected by the search for a global optimum. The movement of the individuals in the search space is based on a discrete-time dynamic filter, and various choices of this filter are possible to obtain different dynamics of the centroids. In this way, a general framework is defined where well-known algorithms represent a particular case. The proposed algorithm is validated through a set of problems, which include non-separable problems, and compared with state-of-the-art algorithms for global optimization

Self-Affine Tilings with Several Tiles, I

AbstractThe tilings of Rd by a finite number of lattice translates of self-affine prototiles are studied in their own right and as they relate to multiwavelet bases of L2(Rd)

A multi-objective optimization algorithm based on self-organizing maps applied to wireless power transfer systems

In this work, a new multi-objective population-based optimization algorithm is presented and tested. In this contribution, the concepts of fast non-dominating sorting and density estimation using the crowding distance are used to create a multi-objective optimization algorithm based on previous work, which is a single objective evolutionary optimization algorithm based on self-organizing maps (SOMs). The SOMs paradigm introduces a strong collaboration between neighbors solutions that improves exploitation. Furthermore, the representative power of the SOMs enhances the exploration and diversification. A state of the art benchmark approach is used to evaluate the performance of the proposed algorithm, obtaining positive results. The test problem uses an analytical model of an inductively coupled wireless power transfer system (WPT). The objective is to optimize the WPT model characteristics in order to allow simultaneous data and power transfer between the coils. The WPT design approach uses more degrees of freedom than existing techniques leading to a number of solutions where both the power signals and the data signal can coexist on the same physical channel achieving good figures of merit