Digital radios have undergone an astonishing evolution in the last century. Born as a set of simple and
power-hungry electrical and electromechanical devices for low data rate transmission of telegraph data
in the Marconi age, they have transformed, thanks to substantial advances in electronic technology,
into a set of small, reliable and sophisticated integrated devices supporting broadband multimedia
communications. This, however, would not have been possible unless significant progress had been
made in recent decades in the field of signal processing algorithms for baseband and passband signals.
In fact, the core of any modern digital radio consists of a set of algorithms running over programmable
electronic hardware. This book stems from the research and teaching activities of its co-authors in
the field of algorithmic techniques for wireless communications. A huge BODY of technical literature
has accumulated in the last four decades in this area, and an extensive coverage of all its important
aspects in a single textbook is impossible. For this reason, we have selected a few important topics
and, for ease of reading, organized them into two parts.
Electrostatic discharge (ESD) is one of the most prevalent threats to the reliability
of electronic components. It is an event in which a finite amount of charge is trans-
ferred from one object (i.e., human BODY) to another (i.e., microchip). This process
can result in a very high current passing through the microchip within a very short
period of time, and, hence, more than 35% of chip damages can be attributed to an
ESD-related event. As such, designing on-chip ESD structures to protect integrated
circuits against the ESD stresses is a high priority in the semiconductor industry.
December 2007, San Jose, California: It seems a long time ago.
I walked into a big networking company to head their small
Power over Ethernet (PoE) applications team. Surprisingly,
I hardly knew anything about PoE prior to that day, having been a
switching-power conversion engineer almost all my life. But it
seemed a great opportunity to widen my horizons. As you can see,
one notable outcome of that seemingly illogical career choice five
years ago is the book you hold in your hands today. I hope this small
BODY of work goes on to prove worthy of your expectations and also
of all the effort that went into it. Because, behind the scenes, there is a
rather interesting story to relate—about its backdrop, intertwined
with a small slice of modern PoE history, punctuated by a rather res-
tive search for our roots and our true heroes, one that takes us back
almost two centuries
Despite the development of a now vast BODY of knowledge known as
modern control theory, and despite some spectacular applications of this
theory to practical situations, it is quite clear that much of the theory has
yet to find application, and many practical control problems have yet to find
a theory which will successfully deal with them. No book of course can
remedy the situation at this time. But the aim of this book is to construct
one of many bridges that are still required for the student and practicing
control engineer between the familiar classical control results and those of
modern control theory.
Despite the development of a now vast BODY of knowledge known as modern
control theory, and despite some spectacular applications of this theory to practical
situations, it is quite clear that some of the theory has yet to find application, and
many practical control problems have yet to find a theory that will successfully deal
with them. No one book, of course, can remedy the situation. The aim of this book
is to construct bridges that are still required for the student and practicing control
engineer between the familiar classical control results and those of modern control
theory.
入室搶劫事件屢見不鮮,針對此現(xiàn)象進(jìn)行分析不難發(fā)現(xiàn),造成失竊事件的極大原因是人們慵懶和意識差等不良性格造成習(xí)慣性不鎖門.本文以STC89C52單片機(jī)為基礎(chǔ),設(shè)計(jì)了一種基于人體紅外傳感器的自動關(guān)門鎖門裝置,來解決此類問題.The incidents of burglary are so common. It is not difficult to find that the main reason for the burglary is the habit of unlocking of doors caused by people's laziness and poor consciousness. Based on the single chip microcomputer of STC89C52, a device used with infrared sensor of human BODY is introduced in this paper, which can achieve the effect of automatic closing and locking doors.
