Abstract: Methods and apparatuses are provided for adjusting a transmit power at a first electronic device. A first Transmit Power Control (TPC) request message, including power mode information of the first electronic device, is transmitted from the first electronic device to a second electronic device. The first electronic device receives a first TPC report message, including power mode information of the second electronic device, transmit power information of the second electronic device, and link margin information for the first electronic device, from the second electronic device. The first electronic device adjusts the transmit power according to the power mode information of the second electronic device, using the transmit power information and the link margin information included in the first TPC report message.

Abstract: Provided herein a method for allocating storage space using a buddy allocator, the method including receiving, by a buddy allocator, a block allocation request from a space allocation requestor, selecting, by the buddy allocator, a first buddy in response to the block allocation request, wherein the first buddy is one of a plurality of buddies, checking, by the buddy allocator, whether blocks of the first buddy include a first spare storage space to which storage space corresponding to the block allocation request is allocated, allocating, by the buddy allocator, the storage space to the blocks of the first buddy when it is checked that the blocks of the first buddy include the first spare storage space, and deallocating, by the buddy allocator, excess storage space of allocated storage space when a size of the allocated storage space is greater than the storage corresponding to the block allocation request, wherein the excess storage space is not corresponding to the block allocation request.

Abstract: Disclosed herein is a method and apparatus for supporting virtualization. In the method, conversion of source code of a loadable module is initiated. A virtualization-sensitive instruction is searched for during the conversion of the source code. If the virtualization-sensitive instruction has been found, a virtualization-sensitive instruction table is generated based on the found virtualization-sensitive instruction. The virtualization-sensitive instruction is substituted with an instruction recognizable in a privileged mode, based on the generated virtualization-sensitive instruction table. The loadable module is loaded and executed in a kernel. Accordingly, the present invention supports virtualization, thus minimizing overhead occurring in full virtualization, and guaranteeing the high performance provided by para-virtualization without modifying a source.

Abstract: Provided are an optical pickup device and an optical disk drive including the same. The optical pickup device includes a quarter-wave plate (QWP) that is disposed parallel to an objective lens and a reflection mirror that reflects a beam back onto the QWP after the beam passed through the QWP. The optical pickup device also includes a polarization mirror that is disposed between the objective lens and the QWP, and which reflects the beam which is generated from a light source onto the QWP, and allows the beam reflected by the reflection mirror to pass through to the objective lens.

Abstract: Methods and apparatuses are provided for adjusting a transmit power at a first electronic device. A first Transmit Power Control (TPC) request message, including power mode information of the first electronic device, is transmitted from the first electronic device to a second electronic device. The first electronic device receives a first TPC report message, including power mode information of the second electronic device, transmit power information of the second electronic device, and link margin information for the first electronic device, from the second electronic device. The first electronic device adjusts the transmit power according to the power mode information of the second electronic device, using the transmit power information and the link margin information included in the first TPC report message.

Abstract: An OS switching method for switching an OS within several seconds in an information processing system is provided. In the information processing system which includes a processor, a main memory, a nonvolatile memory, and a plurality of input/output apparatuses, an OS switcher is executed when power is applied to the information processing system. When a first OS acquires an OS switch command that indicates a switch to a second OS while the first OS is activated and running, the first OS stores identification information of the second OS and information indicating an OS switch in the nonvolatile memory, and performs STR. The OS switcher switches an OS from the first OS to the second OS after the STR is completed. Accordingly, in the system, one OS can be quickly switched to another OS within several seconds, and a previous working environment can be maintained.

Abstract: In order to synchronize a file between transmitting and receiving nodes, when a file is changed, a hint provider of the transmitting node provides a change file and change information about the change file as a hint to a change log generator, the change log generator generates a change log with reference to the change file and the hint, and the generated change log is transmitted to the receiving node by a change log transmitter.

Abstract: Disclosed herein is a network selecting apparatus including: a determining unit checking an operation state of a cache server in which replicated data corresponding to a data request signal are stored and determining whether the cache server is normally operated, when the data request signal is received from a client; and a selecting unit selecting a first network so that the replicated data are transmitted to input and output devices when the cache server is normally operated and selecting a second network so that original data corresponding to the data request signal are transmitted from a storage server in which the original data are stored to the input and output devices when the cache server is not normally operated.

Abstract: There are provided a system and method for providing a virtual desktop service using a cache server. A system for providing a virtual desktop service according to the invention includes a host server configured to provide a virtual desktop service to a client terminal using a virtual machine, a distributed file system configured to store data for the virtual machine, and a cache server that is provided for each host server group having at least one host server, and performs a read process or a write process of data using physically separate caches when the read process or write process of the data is requested from the virtual machine in the host server.

Abstract: Provided are an optical pickup and an optical system using the same. The optical pickup may include an aperture that is disposed at a side where a light beam is incident on an objective lens. The aperture may limit a range of the light beam such that a width of the light beam incident on the objective lens in a first direction is less than a width in a second direction that is perpendicular to the first direction.

Abstract: An optical pickup device, an optical disk drive and method of controlling light performed by the optical pickup device are provided. The optical pickup device includes: a light transmitting system including an object lens for facing a medium having a multi recording layer for storing information, a light source system for providing a plurality of beams used to record information on or reproduce information from the multi recording layer via the light transmitting system, a light-receiving system disposed on a path of a beam reflected from the medium, and a light controller including a light control device for controlling stray light generated in the medium such that the stray light does not reach the light-receiving device.

Abstract: Provided are an optical pickup device and an optical disk drive including the same. The optical pickup device includes a quarter-wave plate (QWP) that is disposed parallel to an objective lens and a reflection mirror that reflects a beam back onto the QWP after the beam passed through the QWP. The optical pickup device also includes a polarization mirror that is disposed between the objective lens and the QWP, and which reflects the beam which is generated from a light source onto the QWP, and allows the beam reflected by the reflection mirror to pass through to the objective lens.

Abstract: An optical pickup and an information storage medium system using the same. The optical pickup includes a light source that emits light having a plurality of different wavelengths. The optical pickup includes a diffraction device having a plurality of diffraction patterns corresponding to the plurality of different wavelengths to divide the light incident from the light source unit into main light and sub light. The optical pickup further includes a photo-detector having a first main light reception unit that receives the main light and a first sub light reception unit that receives the sub light so as to detect an information signal and/or an error signal by receiving reflected light. The first sub light reception unit of the photo-detector is shaped so as to reduce reception of noise sub light due to diffraction based on an undesired diffraction pattern of sub light generated the diffraction device.

Abstract: A method of generating a 1-beam tracking error signal (TES), an optical pickup device, and an optical disc drive device adopting the method. A light-receiving element receives a single reflection beam and detects an alternating current (AC) component and a direct current (DC) component from each of areas formed on two sides of a data track. A servo unit generates a TES by adding and subtracting the AC component and the DC component.

Abstract: An optical pickup device, an optical drive using the same, and a method of forming a beam spot are provided. The optical pickup includes a light source system that includes a light source corresponding to at least one of a digital versatile disc (DVD) and a Blu-ray disc (BD). The light source forms a beam spot having an oval shape with a long axis and a short axis on an information recording track of the disc, and the light source is disposed such that the long axis is maintained at an angle ranging from 0° to 30° with respect to a radial direction passing through a rotation center of the disc.

Abstract: Provided are an optical pickup and an optical system employing the optical pickup. The optical pickup includes a twin light source. In various aspects, a length between the two light sources of a twin light source is reduced while the magnification of the optical pickup is increased, in comparison to a conventional optical pickup. Accordingly, a manufacturing cost of the optical pickup may be reduced.

Abstract: A compatible optical pickup including an optical unit and a focusing unit. The optical unit emits a short wavelength light for high-density recording media and a long wavelength light for low-density recording media, directs the short and long wavelength light to a recording medium, receives lights reflected by the recording medium, and detects an information reproduction signal and/or an error signal from the received lights. The focusing unit focuses light received from the optical unit to form a light spot on a recording surface of the recording medium, diffracts the short wavelength light into a zero order light and the long wavelength light into a second order light to be used as effective light for recording and/or reproduction. Thus, a high-density recording medium and a low-density recording medium having different thicknesses can be compatibly used.

Abstract: An optical pickup device corresponding to an optical recording medium having a plurality of recording layers, and an optical drive using the device are provided. The optical pickup device includes a collimator lens disposed between an object lens and a light source. The collimator lens adjusts a focal length with respect to the optical recording medium, and the object lens focuses light passing through the collimator lens, on the optical recording medium. The object lens is optically optimized for an upper or second-upper recording layer of the optical recording medium.

Abstract: An optical pickup, photodetector, and optical drive adopting the optical pickup are provided. The optical pickup may include a light emitting system having a plurality of light sources corresponding to a plurality of mediums a light receiving system including a photodetector for converting light reflected from a medium into an electrical signal. The photodetector may include first and second light receiving sensors corresponding to the plurality of mediums, each of the first and second light receiving sensors comprising a plurality of regions, each region comprising a plurality of sectors. The plurality of regions of the first and second light receiving sensors may include shared sectors that are shared by the first and second light receiving sensors and exclusive sectors that are exclusively used in the first light receiving sensor or the second light receiving sensor.

Abstract: An OS switching method for switching an OS within several seconds in an information processing system is provided. In the information processing system which includes a processor, a main memory, a nonvolatile memory, and a plurality of input/output apparatuses, an OS switcher is executed when power is applied to the information processing system. When a first OS acquires an OS switch command that indicates a switch to a second OS while the first OS is activated and running, the first OS stores identification information of the second OS and information indicating an OS switch in the nonvolatile memory, and performs STR. The OS switcher switches an OS from the first OS to the second OS after the STR is completed. Accordingly, in the system, one OS can be quickly switched to another OS within several seconds, and a previous working environment can be maintained.