Abstract: There is provided a method and apparatus for displaying a watermark on a screen. According to the present invention, when an application is executed or a document is opened by a user's manipulation, it is determined whether a watermark is displayed based on a message generated from an operating system and screen watermark display policies, and when it is determined that the watermark is displayed, the watermark is displayed on a screen. According to the present invention, when the watermark is displayed on a screen, it is possible to provide a user with notification that corresponding content is important content or confidential content. Even when the screen is captured or is imaged using a camera, the watermark is displayed in the captured image or the imaged video. Therefore, it is possible to identify that the corresponding content is important content or confidential content. As a result, it is possible to increase user awareness of security.

Abstract: There is provided a method and apparatus for displaying a watermark on a screen. According to the present invention, when an application is executed or a document is opened by a user's manipulation, it is determined whether a watermark is displayed based on a message generated from an operating system and screen watermark display policies, and when it is determined that the watermark is displayed, the watermark is displayed on a screen. According to the present invention, when the watermark is displayed on a screen, it is possible to provide a user with notification that corresponding content is important content or confidential content. Even when the screen is captured or is imaged using a camera, the watermark is displayed in the captured image or the imaged video. Therefore, it is possible to identify that the corresponding content is important content or confidential content. As a result, it is possible to increase user awareness of security.

Abstract: A digital demodulator which removes frequency and phase errors existing in a digital signal and converting the error-removed digital signal into a base band signal. The digital demodulator uses a frequency that is twice the transmission rate as the frequency of the sampling clock signal of an analog-to-digital (A/D) converter, and demodulates a received signal in a digital processing using the A/D converter which is low-speed. Thus, all of the received signal processing becomes digitized.