Welcome to AESS tutorial II

In the editorial comment that accompanied our first tutorial I suggested that there be two sorts of tutorial articles. The first is perhaps the more traditional: it provides a reference on an established topic by one of its masters. This would be a topic whose acquaintance many readers will already have made, but whose underpinnings are mysterious for most. We have two of those here. There is a review of distributed power systems (specifically ones working with direct current) by Shiguo Luo and Issa Batarseh. Thanks to our past editor Henry Oman, our magazine has been home to many nice articles on electric power and batteries, particularly with aeronautic and space applications for which power is such an issue. It is appropriate that we begin to represent this with a tutorial, and I thank our T-AES associate editors Polivka and Simoes for recommending this article to me. The second is from Brian Sadler, who has been kind enough to prepare for us as a compendium of what's important in the emerging field of sensor networks. If you follow trends you'll realize that there has been one toward these. Do we need better (and more expensive) (and probably less robust) stand-alone sensors, or is it more efficient and more effective to assign one’s surveillance task to a large network of dumb (read: cheap) sensors? The answer is probably yes, at least if you can figure out how they communicate with each other and with you.