Abstract: A cover for a mobile computing device includes two or more hinges so constructed that the hinges are substantially rigid when in-plane and flexible when out-of-plane. The cover includes segments made of a rigid material disposed between the hinges. The cover, when swiveled to the back side of the computing device, forms a contour around an object such as a stylus to secure the object to the back side of the computing device when the object is present. The cover becomes substantially flat and parallel to the back side of the computing device when the object is absent.

Abstract: A cover for a mobile computing device is described. The cover comprises two or more hinges so constructed that the hinges are substantially rigid when in-plane and flexible when out-of-plane. The cover includes segments made of a rigid material disposed between the hinges, The cover, when swiveled to the back side of the computing device, forms a contour around an object such as a stylus to secure the object to the back side of the computing device when the object is present. The cover becomes substantially flat and parallel to the back side of the computing device when the object is absent.

Abstract: Systems and methods for accurately measuring power output of a cyclist using a bike trainer that may be operated by a user for stationary riding when coupled to a conventional bicycle. The systems utilize a power output equation that models power due to resistance of a fan of the bike trainer as well as power due to kinetic energy of the fan. The systems account for operating conditions that affect the power measurements so that more accurate measurements can be provided, thereby improving the training experience of the user. Operating conditions include mechanical drag, temperature, humidity, and atmospheric pressure and/or altitude. The power output equation is dependent on the angular velocity of the fan of the bike trainer and the measured or received operating conditions.