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: A multi-power supply system and a control method thereof are disclosed. The multi-power supply system includes a first power-supply unit, a second power-supply unit, a switching unit, and a control unit. The power-supply unit comprises a reverse current prevention circuit, a converter circuit, and an input circuit. The switching unit is electrically coupled to the first power-supply unit and the second power-supply unit. When the first and second input circuits are in normal operation, the control unit controls the switching unit to be turned off to allow the first power-supply unit and the second power-supply unit to supply power to a load. When one of the first and second input circuits is in abnormal operation, the control unit controls the switching unit to be turned on. The switching unit cooperates with the first and second reverse current prevention circuits to achieve the switching of input.

Abstract: A resonant converter apparatus includes a first pre-regulator, a first resonant converter, a second pre-regulator, a second resonant converter and a controller. The first pre-regulator receives a first input voltage and generates a first output voltage. The first resonant converter receives the first output voltage and generates a supply voltage. The second pre-regulator receives a second input voltage and generates a second output voltage. The second resonant converter receives the second output voltage and generates the supply voltage, in which an output of the second resonant converter is electrically connected in parallel with an output of the first resonant converter. The controller controls the first pre-regulator and the second pre-regulator such that the first resonant converter and the second resonant converter generate identical output currents in accordance with controlled operations of the first pre-regulator and the second pre-regulator.

Abstract: An optical fiber connector includes a ferrule, a fastening tube, and a cover plate. The ferrule includes a through hole and a breach. Front and rear parts of the through hole respectively include a pre-embedded optical fiber and a field optical fiber. A joint of the two optical fibers is located at the breach. A part of the through hole is exposed in the breach. The fastening tube includes a ferrule accommodating portion accommodating a part of the ferrule on which the breach is disposed, and an opening disposed thereon. The opening connects the ferrule accommodating portion, and is positionally corresponding to the breach. The cover plate passes through the opening, is disposed in the breach, and presses the joint. The ferrule is easily machined and can adopt a material hardly influenced by environment temperature. The joint is fixed, and an amount of joint loss is stable.

Abstract: A multi-power supply system and a control method thereof are disclosed. The multi-power supply system includes a first power-supply unit, a second power-supply unit, a switching unit, and a control unit. The power-supply unit comprises a reverse current prevention circuit, a converter circuit, and an input circuit. The switching unit is electrically coupled to the first power-supply unit and the second power-supply unit. When the first and second input circuits are in normal operation, the control unit controls the switching unit to be turned off to allow the first power-supply unit and the second power-supply unit to supply power to a load. When one of the first and second input circuits is in abnormal operation, the control unit controls the switching unit to be turned on. The switching unit cooperates with the first and second reverse current prevention circuits to achieve the switching of input.

Abstract: An optical fiber connector comprises a ferrule, a fastening tube, and a cover plate. The ferrule comprises a through hole and a breach. Front and rear parts of the through hole respectively comprise a pre-embedded optical fiber and a field optical fiber. A joint of the two optical fibers is located at the breach. A part of the through hole is exposed in the breach. The fastening tube comprises a ferrule accommodating portion accommodating a part of the ferrule on which the breach is disposed, and an opening disposed thereon. The opening connects the ferrule accommodating portion, and is positionally corresponding to the breach. The cover plate passes through the opening, is disposed in the breach, and presses the joint. The ferrule is easily machined and can adopt a material hardly influenced by environment temperature. The joint is fixed, and an amount of joint loss is stable.

Abstract: A resonant converter apparatus includes a first pre-regulator, a first resonant converter, a second pre-regulator, a second resonant converter and a controller. The first pre-regulator receives a first input voltage and generates a first output voltage. The first resonant converter receives the first output voltage and generates a supply voltage. The second pre-regulator receives a second input voltage and generates a second output voltage. The second resonant converter receives the second output voltage and generates the supply voltage, in which an output of the second resonant converter is electrically connected in parallel with an output of the first resonant converter. The controller controls the first pre-regulator and the second pre-regulator such that the first resonant converter and the second resonant converter generate identical output currents in accordance with controlled operations of the first pre-regulator and the second pre-regulator.

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.