A heat dissipation unit for radiating heat produced by at least one heat source of an electronic device includes a fan, at least an electrical connector, and a latching member. A non IP-Multimedia-Subsystem network is provided with a non IMS network interworking device, by which the non IMS network is converged with a Voice over Internet Protocol network. The additive is blended with a base polymer and conductive carbon black to form the material for the semiconductive shield. In general the second appearance mode is designed to attract the attention of a user to the peripheral GUI elements, while the first mode is designed to avoid distracting the user from the content of the maximized window. After that, maintenance control is executed in accordance with the calculated score of the degree of abnormality, thereby appropriately avoiding a fault of the communication system. Each array is rotatable around a common axis, and the light sources in each array are arranged so that each light source traverses along a unique path around the common axis.