The disclosure is directed to projectors, optical compensation methods and liquid crystal devices. The method enables a first antenna configuration of the plurality of antennas in accordance with a first pre-determined rule. Maximum drain voltage is determined by drain to gate separation and length of a second, horizontal, channel under the gate. Analytic analysis may then be applied to the tracked user interactions to identify data and actions to sync between the mobile payment application and the other mobile applications on the mobile computing device as well as with other applications on other computing devices of the user that are identified via a user identification. The user may engage the arm assembly with his or her upper body and perform training or exercises involving lifting and lowering the user’s body, moving laterally, or both.