28495632
Iterative signal extrapolation algorithms with wavelets
A generalized Papoulis-Gerchberg (PG) algorithm for signal extrapolation based on the wavelet representation has been recently proposed by Xia, Kuo and Zhang. In this research, we first show that the generalized PG algorithm converges to the minimum norm solution when the wavelet bases are semi-orthogonal (or known as the prewavelet). However, the generalized PG algorithm converges slowly in numerical implementation. To accelerate the convergence rate, we formulate the discrete signal extrapolation problem os a two-step process and apply the steepest descent and conjugate gradient methods for its solution. Numerical experiments are given to illustrate the performance of the proposed algorithms.<<ETX>>
1584599
Embedded coding of 3D graphic models
A progressive compression method which encodes a 3D graphic models into an embedded bit stream is investigated. The coder first encodes the coarsest resolution of the model, and then includes the information of finer details gradually. A rate-distortion model is used in the integration of different types of bit streams into a single embedded bit stream to optimize the overall coding performance. This embedding property can be applied to progressive transmission, multi-resolution editing and level-of-detail control. Numerical experiments are provided to demonstrate the excellent rate-distortion performance of the proposed method.
12549772
Designing an evaluation method for security user interfaces: lessons from studying secure wireless network configuration
: / 28 Ten or 20 years ago, evaluating security products was not as much of a problem as it is today. Systems were managed by people able—and willing—to master the complexities. However, with the proliferation of personal computing devices and network connectivity in the home, systems are now regularly managed by nonexperts. Each system needs to be secured by each user in each home. Therefore designing effective, unbiased evaluation methods for consumer products is one of the first steps in improving both users’ experiences and their security practices. Evaluating the usability of security is a challenge. A common question evaluators face is: “How do I test whether users will configure and use a product securely?” In this article, we outline problems we encountered in evaluating secure wireless network configuration and examine the assumptions many user study methods make, but which may not hold for security.