Abstract: This application relates to a noise signal generating apparatus. In one aspect, the apparatus includes a bandwidth expansion unit configured to generate a noise signal having a second bandwidth by expanding a noise source signal having a first bandwidth to the second bandwidth that is greater than the first bandwidth. The apparatus may also include a randomization unit configured to perform randomization and output the generated noise signal having the second bandwidth.

Abstract: A computer having a speaker outputting a sound, the computer including: a sound signal output unit outputting a speaker sound signal to the speaker; a speaker output control unit controlling whether the sound signal output unit to output the speaker sound signal; and an alarm control unit controlling the speaker output control unit so that the sound signal output unit outputs the speaker sound signal when a predetermined alarm condition is detected, and the sound signal output unit so that the speaker generates a preset alarm sound to correspond to the alarm condition.

Abstract: A computing device allows selective output of audio signals within a frequency band. The computing device has a main system having an audio signal generator generating audio signals, a main audio outputting unit attached to the main system and outputting the generated audio signals, an auxiliary system connected to the main system and receiving the audio signals generated by the audio signal generating unit, and an auxiliary audio outputting unit attached to the auxiliary system and outputting the audio signals received in the auxiliary system A switching unit controls the audio signals to pass through a plurality of selectable filters filtering the audio signals within respective frequency bands and to supply the selected filtered audio signals to the main audio outputting unit, and to the auxiliary audio outputting unit, depending upon whether the auxiliary system is connected to the main system.

Abstract: A computing device allows selective output of audio signals within a frequency band. The computing device has a main system having an audio signal generator generating audio signals, a main audio outputting unit attached to the main system and outputting the generated audio signals, an auxiliary system connected to the main system and receiving the audio signals generated by the audio signal generating unit, and an auxiliary audio outputting unit attached to the auxiliary system and outputting the audio signals received in the auxiliary system A switching unit controls the audio signals to pass through a plurality of selectable filters filtering the audio signals within respective frequency bands and to supply the selected filtered audio signals to the main audio outputting unit, and to the auxiliary audio outputting unit, depending upon whether the auxiliary system is connected to the main system.

Abstract: A portable computer system with universal serial bus (USB) port or ports and a method for controlling power of the universal serial bus (USB) port is described. When the main power of the portable computer system is supplied from a battery rather than an alternating current (AC) adapter, the power of the universal serial bus (USB) port is automatically shut down. In addition, the power of the universal serial bus (USB ) port is completely shut down while the universal serial bus (USB) port is not used in response to a setting state of the universal serial bus (USB) port, thereby reducing unnecessary power consumption. Further, when an over-current is detected from the alternating current (AC) adapter or the battery, the power of the universal serial bus (USB) port is shut down, whereby damage to peripheral devices coupled to the universal serial bus (USB) port can be prevented.