Abstract: A method and apparatus for controlling parameters of a wireless data streaming system are provided. The method of controlling parameters of a wireless data streaming system includes controlling first parameters, which can be controlled in units of individual packets, according to a current packet transmission state in a data stream; transmitting a predefined number of packets using the first parameters and obtaining statistical information regarding use of the first parameters in the transmission of the predefined number of packets; and controlling second parameters, which can be controlled in units of packet groups, with reference to the statistical information and a desired quality of service (QoS).

Abstract: Provided is an operating voltage scaling method for a portable terminal. The method includes, if reproduction of a moving image is requested, acquiring DYNamicity (DYN) of the reproduction-requested moving image, determining whether frame skipping is possible for the moving image according to the acquired DYN of the moving image, and if it is determined that frame skipping is possible for the moving image, supplying a low operating voltage to a controller of the mobile terminal to control the mobile terminal to operate with a low-speed clock, and reproducing the moving image while skipping a frame.

Abstract: An apparatus and method for transmitting a multimedia data stream are provided. The apparatus includes a data source unit to output the data stream; a frame dividing unit to divide the data stream according to a type of a video frame included in the data stream and to output the divided data stream; a parameter control unit to select a parameter set for separate transmission control of the divided data stream using parameters for controlling a transmission layer; and a network interface unit to control transmission of the divided data stream using the parameter set. The method includes dividing the data stream according to a type of a video frame; selecting a parameter set for separate transmission control of the divided data stream; and controlling transmission of the divided data stream using the selected parameter set.

Abstract: A method and apparatus to restore a system using virtualization, the method including: if a system restoration at a target restoration time point from among at least one restoration time points is requested, generating a virtualization layer; if a use of a system is requested by an application layer, accessing the target restoration time point using the virtualization layer; and performing a system restoration at the accessed target restoration time point.

Abstract: A virtual environment system and a method of operating the same, the virtual environment system including: a virtual operating system (OS) unit to operate a virtual OS installed in a mobile storage medium in a host OS installed in a host computer, to attach a virtual resource included in the virtual OS to the host OS, and to perform arbitration so that a virtual process operated in the virtual OS uses the virtual resource; and a user interface unit to provide a virtual desktop screen so that a user can use the virtual process in the virtual environment provided by the virtual OS.

Abstract: A method and apparatus for inputting and outputting data by using a virtualization technique are provided. The method includes generating a virtual operating system (OS) for the external device, which is connected to a host, based on OS information stored in the external device, setting a partial area of a storage of the host as virtual storage for the external device, and storing the data in the virtual storage or a memory of the external device in response to a request for inputting and outputting the data from the virtual OS.

Abstract: A method of mutually authenticating between a local host and a software mobility device including an operating system virtualization layer, and a method of forming an input/output (I/O) channel. The method of authenticating a local host in the software mobility device includes requesting a certificate from the local host in which an integrity value of the local host is stored, and receiving the certificate from the local host; receiving an integrity value measured in the local host and comparing the measured integrity value with the integrity value included in the certificate to verify the local host; and when the local host is verified, encrypting a security profile of the software mobility device and transmitting the encrypted security profile to the local host so as to provide secure communication between the local host and the software mobility device.

Abstract: Provided is a method of controlling memory access. In a system including a first layer element executed in a privileged mode having a first priority of permission to access the entire region of a memory and second and third layer elements executed in an unprivileged mode having a second priority of permission to access a partial region of the memory, the method of controlling memory access determines whether the memory is accessible for each page that is an address space unit, based on which mode a layer element currently accessing the memory is executed in between the privileged mode and the unprivileged mode; and determines whether the memory is accessible based on which one of the first, second and third layer elements corresponds to a domain currently being attempted to be accessed from among a plurality of domains of the memory.

Abstract: An apparatus and method are provided for variably transmitting a multimedia stream according to requirements of a client device and the state of a channel. The multimedia stream transmission apparatus includes: a plurality of virtual machines corresponding to the multiple client applications, each of the virtual machines determining a specific parameter set and obtaining a change value for the parameter set from network statistics and a requirement of a corresponding client application; a parameter adjustment unit which adjusts values of parameters used in a network interface by the change value; and the network interface which transmits the multimedia stream based on the adjusted parameters.

Abstract: A method and apparatus for controlling parameters of a wireless data streaming system are provided. The method of controlling parameters of a wireless data streaming system includes controlling first parameters, which can be controlled in units of individual packets, according to a current packet transmission state in a data stream; transmitting a predefined number of packets using the first parameters and obtaining statistical information regarding use of the first parameters in the transmission of the predefined number of packets; and controlling second parameters, which can be controlled in units of packet groups, with reference to the statistical information and a desired quality of service (QoS).

Abstract: A data transmission method and apparatus encodes data to be transmitted over a wireless network on a unit basis, and provides the transmission data with information for allowing the transmission data to recover from an error being added thereto, transmits the transmission data to the wireless network, calculates a transfer success ratio depending on whether the transmission data have been successfully transmitted, and controls the transmission of the transmission data depending on whether the transfer success ratio is higher than a threshold value.

Abstract: An apparatus and method for transmitting a multimedia data stream are provided. The apparatus includes a data source unit to output the data stream; a frame dividing unit to divide the data stream according to a type of a video frame included in the data stream and to output the divided data stream; a parameter control unit to select a parameter set for separate transmission control of the divided data stream using parameters for controlling a transmission layer; and a network interface unit to control transmission of the divided data stream using the parameter set. The method includes dividing the data stream according to a type of a video frame; selecting a parameter set for separate transmission control of the divided data stream; and controlling transmission of the divided data stream using the selected parameter set.