Class-dependent discretization for inductive learning fromcontinuous and mixed-mode data

Inductive learning systems can be effectively used to acquire classification knowledge from examples. Many existing symbolic learning algorithms can be applied in domains with continuous attributes when integrated with a discretization algorithm to transform the continuous attributes into ordered discrete ones. In this paper, a new information theoretic discretization method optimized for supervised learning is proposed and described. This approach seeks to maximize the mutual dependence as measured by the interdependence redundancy between the discrete intervals and the class labels, and can automatically determine the most preferred number of intervals for an inductive learning application. The method has been tested in a number of inductive learning examples to show that the class-dependent discretizer can significantly improve the classification performance of many existing learning algorithms in domains containing numeric attributes     

Modeling multi-rate DSP specification semantics for formal transformational design in HOL

The CATHEDRAL Silicon Compilers synthesize hardware for DSP algorithms specified in Silage, a high level applicative language. In order to optimize the results of the silicon compilation in terms of chip-area and/or throughput, the user often massages the specification applying transformations to the Silage code. To guarantee that the transformations preserve the behavior of the specified algorithm, the formal semantics of the specification language had to be defined. The semantics has been used to prove in HOL the correctness of the transformations and to prove properties of the specification. We are currently building a system where a menu of useful andcorrectness preserving transformations will be available to the user. In this system the user could choose appropriate transformations from the menu taking advantage of his creativity and expertise to interactively guide the silicon compiler, without the risk of introducing inconsistencies. This article describes the formalmulti-rate semantics of a substantial subset of Silage and illustrates some formally verified transformations.     

Flow control in message-switched communications networks

A queueing network model is used to analyse the performance of flow-control techniques. Analytical expressions for throughput and mean end-to-end delay are derived. Numerical results show that, under isarithmic control, the total network throughput is degraded significantly when the demand from one user is increased. Throughput degradation can be avoided if an end-to-end or a two-level control is used. Of these two schemes, the two-level control gives a higher throughput to the user with increased demand. This often results in a higher total throughput. The mean end-to-end delay of the various flow-control techniques is also characterized.     

Efficient waveguide Bragg-deflection grating on LiNbO3

An efficient Bragg-deflection grating on x-cut LiNbO3, using proton exchange in benzoic acid through an aluminium grating mask, has been demonstrated. A deflection efficiency of 90% has been measured.     

Sequential Destruction Method for Monte Carlo Evaluation of System Reliability

Circumstances favoring the use of Monte Carlo methods for evaluating the reliability of large systems are discussed. A new method, that of Sequential Destruction (SD) is introduced. The SD method requires no preparatory topological analysis of the system, and remains viable when element failure probabilities are small. It applies to a variety of reliability measures and does not require element failures to be s-independent. The method can be used to improve the performance of selective sampling techniques. Substantial variance reductions, as well as computational savings, are demonstrated using a sample system with more than 100 elements.     

Molecular beam epitaxy of CuCl films on mica

Molecular beam epitaxy of pure CuCl films on mica was studied for various substrate temperatures (16–250 °C). Both the transmission Laue method and diffractometer methods were used to characterize the films. All films showed the [111] zinc blende texture but only those films prepared at about 150 °C showed excellent, though twinned, epitaxy.