Most Popular Books by David Christian

This a companion reader for the website World History for Us All, a site with free online lesson plans. http://worldhistoryforusall.sdsu.edu This reader is edited for language accessible to grades 6–9 and contains Big Eras One–Seven.

A Rotorcraft UAV provides an ideal experimental platform for vision-based navigation. This thesis describes the flight tests of the US Army PALACE project, which implements Moravec''s pseudo-normalized correlation tracking algorithm. The tracker uses the movement of the landing site in the camera, a laser range, and the aircraft attitude from an IMU to estimate the relative motion of the UAV. The position estimate functions as a GPS equivalent to enable the rotorcraft to maneuver without the aid of GPS. Flight tests were performed with obstacles and over concrete, asphalt, and grass in daylight conditions with a safe landing area determined by a separate method. The tracking algorithm and position estimation performance are compared to GPS. Accurate time synchronization of the inputs to the position estimation algorithm directly affect the closed-loop stability of the system, proportional with altitude. By identifying the frequency response of each input and adding filters to delay some of the inputs, the closed-loop system maintains stable flight above 18 m above ground, where the system was unstable without the additional filters.

Power of The Pros explains in depth the techniques that the worlds hardest hitting fighters use to knock out and dominate their opponents. The book comes with 30 minutes of extensive companion videos, accessible on an exclusive webpage. (Link and password include in the book.) Each section explores another way that the worlds greatest boxers, kickboxers, and MMA fighters have used the laws of physics and biomechanics to generate massive power. The concepts are explained in a clear, no nonsense way, with lots of drills and examples to help you put these techniques to good use. The book and videos are from David Christian, lifetime martial artist and creator and producer of The Modern Martial Artist youtube channel. The channel has over 5 million views, with videos featured on The Guardian''s webpage and Mixed Martial Arts .com.