Abstract: A positioning method and system are provided. The positioning method includes the steps of utilizing at least one electronic device to establish a calibration database corresponding to an irregular grid of reference location points which are defined in an environment; utilizing a mobile device to detect Wi-Fi access points in the environment; utilizing the mobile device to estimate the signal strengths of the detected Wi-Fi access points to generate an estimated result; utilizing a positioning terminal to compare the estimated result and data stored in the calibration database by a weighed K-Nearest neighbor location algorithm to generate a comparison result; and utilizing the positioning terminal to estimate the location of the mobile device according to the comparison result.

Abstract: A method of measuring motion power and resistance coefficient of a bicycle measures sensed data including at least one front projecting area of a bicycle ridden by a user, an air temperature value, an air pressure value, a traveling speed value, an acceleration value, a relative wind speed value, an inclination value and a total weight value to calculate an air resistance coefficient, a rolling friction coefficient of a bicycle tire, a force and a motion power applied to the bicycle by the user, so that the user may learn a better riding posture for different riding conditions and reduce the air resistance effectively by adjusting the riding posture, so as to reduce the consumed motion power. Through the installation of a display unit, the user may know about the data sensed by the sensor and the computation result of the processing unit anytime.

Abstract: A global positioning system device and an ionosphere error estimation method thereof are provided. The global positioning system device is connected to a plurality of dual-band base stations, and receives a plurality of ionosphere pierce point coordinates and a plurality of ionosphere errors from the dual-band base stations. The global positioning system device calculates a user ionosphere error by an interpolation method based on the ionosphere pierce point coordinates and the ionosphere errors of the dual-band base stations and a user ionosphere pierce point coordinate of the global positioning system device.

Abstract: A global positioning system device and an ionosphere error estimation method thereof are provided. The global positioning system device is connected to a plurality of dual-band base stations, and receives a plurality of ionosphere pierce point coordinates and a plurality of ionosphere errors from the dual-band base stations. The global positioning system device calculates a user ionosphere error by an interpolation method based on the ionosphere pierce point coordinates and the ionosphere errors of the dual-band base stations and a user ionosphere pierce point coordinate of the global positioning system device.