Abstract: An apparatus of a terminal performs an operation method of the terminal using a cloud system. The method includes sending a request for information of a server providing a specific service, to at least one broker. The method also includes receiving the information of the server from the broker, and sending a request for the specific service to the server, using the information of the server.

Abstract: A method of centering a disk of a hard disk drive includes arranging a disk on an upper end portion of a hub on which a plurality of disks are rotatably assembled, and assembling the disk on the hub by vibrating the hub. Accordingly, the disks and/or spacers may be easily assembled on the hub, a time of centering may be relatively much reduced, and a superior centering quality may be obtained.

Abstract: A servo track writing method and a servo track write system of a hard disk drive (HDD) using the servo track write method. The servo track writing method includes performing a reference check (R/C) on a first servo pattern which is pre-written on a first surface of a disk, and if the R/C determines that a quality of the first servo pattern is not good, erasing a specific area of the first servo pattern and writing a second servo pattern on a second surface of the disk. Therefore, process time delay factors of a series of rework processes of writing servo patterns on a disk are removed to shorten a process time of the rework processes. In addition, productivity of a HDD is improved.

Abstract: A method of operating a servo track writer includes writing a clock pattern signal to a magnetic recording medium of a head disk assembly, reading the clock pattern signal written to the magnetic recording medium and dividing a frequency of a read clock pattern signal, and supplying a clock pattern signal having a divided frequency to a spindle motor for rotating the magnetic recording medium.

Abstract: A method of centering a disk of a hard disk drive includes arranging a disk on an upper end portion of a hub on which a plurality of disks are rotatably assembled, and assembling the disk on the hub by vibrating the hub. Accordingly, the disks and/or spacers may be easily assembled on the hub, a time of centering may be relatively much reduced, and a superior centering quality may be obtained.

Abstract: A method of writing a servo pattern of a hard disk drive includes measuring the speed of a head of the hard disk drive by reading a basic servo pattern written to only select ones of the data tracks of the disk, realizing a feedforward current profile when the difference between the actual speed of the head and a target speed of the head is within a predetermined range, and writing a reference servo pattern using the realized feedforward current profile. A final servo pattern is then written using the reference servo pattern.

Abstract: A method of detecting a free fall of a device includes measuring an acceleration of the device, calculating an integral of the acceleration, and determining whether the acceleration is periodic. If the acceleration is not periodic, the integral of the acceleration is compared with a first critical value to determine whether the device falls freely. If the acceleration is periodic, the integral of the acceleration is compared with a second critical value to determine whether the device falls freely. The first and second critical values are different. Since whether the device is periodically accelerated is considered, free fall of the device can be correctly detected, and thus malfunction of the device can be prevented. For example, an unnecessary protection operation for a hard disk drive of the device can be prevented, and thus a user can conveniently use the device.

Abstract: A servo track writing method and a servo track write system of a hard disk drive (HDD) using the servo track write method. The servo track writing method includes performing a reference check (R/C) on a first servo pattern which is pre-written on a first surface of a disk, and if the R/C determines that a quality of the first servo pattern is not good, erasing a specific area of the first servo pattern and writing a second servo pattern on a second surface of the disk. Therefore, process time delay factors of a series of rework processes of writing servo patterns on a disk are removed to shorten a process time of the rework processes. In addition, productivity of a HDD is improved.

Abstract: A method of detecting a free fall of a device includes measuring an acceleration of the device, calculating an integral of the acceleration, and determining whether the acceleration is periodic. If the acceleration is not periodic, the integral of the acceleration is compared with a first critical value to determine whether the device falls freely. If the acceleration is periodic, the integral of the acceleration is compared with a second critical value to determine whether the device falls freely. The first and second critical values are different. Since whether the device is periodically accelerated is considered, free fall of the device can be correctly detected, and thus malfunction of the device can be prevented. For example, an unnecessary protection operation for a hard disk drive of the device can be prevented, and thus a user can conveniently use the device.

Abstract: A method, an apparatus and a computer readable recording medium storing a program for correctly detecting a free fall by referring to an acceleration and an integration of the acceleration. The method includes sensing an acceleration of the mobile device; integrating the sensed acceleration with respect to time; and determining the free fall by comparing the result of the integrating with a predetermined area threshold.