Abstract: Provided is a projection device, including a casing, a light source module, an optical engine module, a projection lens, and a fan. The casing includes a right cover plate and a baffle opposite to each other, and a lower cover plate adjacent to the right cover plate. The baffle divides the casing into first and second areas. The right and lower cover plates respectively have first and second air outlets adjacent to each other and located in the second area. The light source module, the optical engine module, located on a light transmission path of the light source module, the projection lens, connected to the optical engine module, and the fan, adjacent to the baffle, are disposed in the first area of the casing. The projection device is placed in a first or second state, and hot airflow therein flows out from the first or second air outlet.

Abstract: A method for positioning a mobile device includes following steps. Based on a prior location point of the mobile device, many sample points are generated according to a prior probability distribution associated with the prior location point. A current moving track or a current moving status of the mobile device is obtained, and the sample points are updated according to at least one of the current moving track and the current moving status. A current estimated position is obtained based on a radio frequency signal received by the mobile device. A current probability distribution of the sample points corresponding to the radio frequency signal or the current estimated position is generated to obtain corresponding weights of the updated sample points. A current location point of the mobile device is obtained according to the weights and distribution of the sample points.

Abstract: A method for positioning a mobile device includes following steps. Based on a prior location point of the mobile device, many sample particles are generated according to a prior probability distribution associated with the prior location point. A current moving track or a current behavior mode of the mobile device is obtained, and the sample particles are moved according to at least one of the current moving track and the current behavior mode. A current supposed status is obtained based on a radio frequency signal received by the mobile device. A current probability distribution of the sample particles corresponding to the radio frequency signal or the current supposed status is generated to obtain corresponding weights of the moved sample particles. A current location point of the mobile device is obtained according to the weights and distribution of the sample particles.