Our last two columns have explored various techniques for using distributed callbacks to decouple clients and servers and create peer-to-peer relationships between the objects in a distributed system. We’ve shown various ways to eliminate the polling required by a stock application client. All these approaches center around direct or indirect callbacks from the Stock Quote Server. Like all engi...

The default solution for mobile robot communication is RFnetworking, typically based on one of the IEEE 802.11 standards also known as WLAN technology. Radio communication frees the robots from umbilical cords. But it suffers from several significant drawbacks, especially limited bandwidth and range. The limitations of both aspects are in addition hard to predict as they are strongly dependent ...

Besides many advantages of wavelet transform, it has several drawbacks, e.g. ringing, shift variance, aliasing and lack of directionality. Some of them can be eliminated by using wavelet packet transform, stationary wavelet transform, complex wavelet transform, adaptive directional lifting-based wavelet transform, or adaptive wavelet filter banks that use either L2 or L1 norm. This paper contai...