Parallel manipulator usually more limited in the workspace; for instance, they generally cannot reach around obstacles. The calculations involved in performing a desired manipulation (forward kinematics) are also usually more difficult and can lead to multiple solutions. Two examples of popular parallel robots are the Stewart platform and the Delta robot. Parallel manipulator A parallel manipulator is a mechanical system that uses several computer-controlled serial chains to support a single platform, or end-effector. Perhaps, the best known parallel manipulator is formed from six linear actuators that support a movable base for devices such as flight simulators. This device is called a Stewart
Serial killer that serial killers are always white might have become "truth" in some research fields due to the over-reporting of white serial killers in the media. According to some sources, the percentage of serial killers who are African American is estimated to be between 13% and 22%. Another study has shown that 16% of serial killers are African American, what author Maurice Godwin describes as a "sizeable portion". A 2014 Radford/FGCU Serial Killer Database annual statistics report indicated that for the decades 1900–2010, the percentage of white serial killers was 52.1% while the percentage of African American serial killers was 40.3%.