Abstract: Embodiments of the present disclosure provide a server data sending method and a server data sending apparatus. The method can include: acquiring, by a server, crystal oscillator error information and operating rate information of a terminal; setting, by the server, preamble length information according to the crystal oscillator error information and the operating rate information; and sending, by the server, a downlink data frame to the terminal, the downlink data frame comprising a preamble aligned with the preamble length information.

Abstract: A heat dissipation assembly and a communication module. The heat dissipation assembly includes a housing and a heat generation device disposed inside the housing, wherein the housing is provided therein with a heat insulation cavity around the periphery of the heat generation device, the heat insulation cavity is provided with a through hole, and the housing is provided therein with a heat conduction assembly disposed through the through hole and configured to conduct the heat of the heat generation device to the housing.

Abstract: Embodiments of the present disclosure provide a server data sending method and a server data sending apparatus. The method can include: acquiring, by a server, crystal oscillator error information and operating rate information of a terminal; setting, by the server, preamble length information according to the crystal oscillator error information and the operating rate information; and sending, by the server, a downlink data frame to the terminal, the downlink data frame comprising a preamble aligned with the preamble length information.

Abstract: This invention relates to a method for preventing a copy of document, belonging to a technical field of entire copy protection of document. In the prior art, for some important documents, specially the secret ones, the reproduction of this kind of document is usually prohibited by its owner because of the security. But the technique in the prior art can not solve the problem of preventing unauthorized reproduction. The method of the present invention is intended to embed a shading pattern under the original image of anti-copy document by an application program installed in the copy device, and decide whether the document can be copied legally or not. By the method of present invention, it is possible to detect the watermark information of the anti-copy document accurately and quickly, and prevent the reproduction of the anti-copy document thoroughly. Moreover, an additional memory space is no need.

Abstract: The invention provides a method and apparatus for performing activity detection on images, by comparing a difference in file sizes of two still images f0 and fd between a predetermined interval, it is judged whether an activity happens on the image within the predetermined interval. Algorithm of the invention is very simple and computation burden thereof will not be affected by size of the detected image or number of pixels.

Abstract: This invention relates to a method for preventing a copy of document, belonging to a technical field of entire copy protection of document. In the prior art, for some important documents, specially the secret ones, the reproduction of this kind of document is usually prohibited by its owner because of the security. But the technique in the prior art can not solve the problem of preventing unauthorized reproduction. The method of the present invention is intended to embed a shading pattern under the original image of anti-copy document by an application program installed in the copy device, and decide whether the document can be copied legally or not. By the method of present invention, it is possible to detect the watermark information of the anti-copy document accurately and quickly, and prevent the reproduction of the anti-copy document thoroughly. Moreover, an additional memory space is no need.