A digital signal processing approach to real-time AC motor modeling

Discrete-time computational models of squirrel-cage AC motors are derived and analyzed for the purpose of advanced motor control. The starting point is a continuous-time model defined by a pair of simultaneous complex-coefficient differential equations. Discrete-time models are derived using both the bilinear transformation and the forward-difference approximation. The exact dependence between stability and the minimum sampling rate in the forward-difference approach is shown. The responses of the two discretized models are compared using real-world motor parameters. Using the forward difference method, a more compact implementation is obtained (although a higher sampling rate is required) as compared to the bilinear transformed model of equivalent performance and 2.7 times higher computational complexity. A 16/24-b DSP-ASIC coprocessor prototype implementing the AC motor model is introduced     

Towards a contingency approach with whitelist- and blacklist-based anti-phishing applications: what do usability tests indicate?

In web browsers, a variety of anti-phishing tools and technologies are available to assist users to identify phishing attempts and potentially harmful pages. Such anti-phishing tools and technologies provide Internet users with essential information, such as warnings of spoofed pages. To determine how well users are able to recognise and identify phishing web pages with anti-phishing tools, we designed and conducted usability tests for two types of phishing-detection applications: blacklist-based and whitelist-based anti-phishing toolbars. The research results mainly indicate no significant performance differences between the application types. We also observed that, in many web browsing cases, a significant amount of useful and practical information for users is absent, such as information explaining professional web page security certificates. Such certificates are crucial in ensuring user privacy and protection. We also found other deficiencies in web identities in web pages and web browsers that present challenges to the design of anti-phishing toolbars. These challenges will require more professional, illustrative, instructional, and reliable information for users to facilitate user verification of the authenticity of web pages and their content.