The dying of Professor Arthur Wright in the summertime of 1996 disadvantaged me of a chum and a colleague whose judgement and event formed this e-book. I pay tribute to his contributions to defense and electric engineering schooling. within the 5 years because the first version seemed, many advancements have taken position and it really is now essential to replace the ebook. using electronic communications and complex sign processing recommendations is now frequent and a number of other absolutely numeric relays can be found from manu­ facturers. new Chapters thirteen and 14 were additional to introduce readers to those suggestions and linked innovations. synthetic intelligence is making its impression in all engineering functions and tool method security is not any exception. specialist structures, fuzzy common sense, man made neural networks, adaptive and built-in safety, synchronized measurements utilizing the worldwide positioning procedure, genetic algorithms, versatile a.c. transmission platforms, are many of the innovations thought of in reference to safeguard. even though a lot of those concepts haven't but chanced on significant program in security, it's however crucial for the proficient safeguard engineer to have a easy realizing of the underlying ideas and technique in order that he, or she, can evaluation their suitability for brand spanking new relaying difficulties and purposes. bankruptcy 15 was once for that reason extra to steer readers via this constructing region. i've got additionally further a few new fabric in different chapters to mirror adjustments over the last years.