Abstract: A radio communication terminal network with a tree structure is formed in such a way that a plurality of receiving side terminal devices on a downstream side of a source terminal device are connected to the source terminal device, and other receiving side terminal devices on a further downstream side are connected to at least one of the plurality of the receiving side terminal devices.

Abstract: A transaction processing system capable of easily and efficiently realizing the file update processing by a plurality of transactions operating in parallel as well as the recovery processing at a time of a fault occurrence is disclosed. In the transaction processing system, a plurality of transactions that carry out update processing with respect to one file read out onto a buffer region are executed, and that one file is written into a stable memory device at a time of commit of one transaction among the plurality of transactions, where that one file contains a content of committed updates made by that one transaction and a content of non-committed updates made by other non-committed transactions, and information for cancelling the non-committed updates.

Abstract: A transaction processing system capable of easily and efficiently realizing the file update processing by a plurality of transactions operating in parallel as well as the recovery processing at a time of a fault occurrence is disclosed. In the transaction processing system, a plurality of transactions that carry out update processing with respect to one file read out onto a buffer region are executed, and that one file is written into a stable memory device at a time of commit of one transaction among the plurality of transactions, where that one file contains a content of committed updates made by that one transaction and a content of non-committed updates made by other non-committed transactions, and information for cancelling the non-committed updates.

Abstract: A data allocation control method is applicable to a data recording apparatus for writing and/or reading data to/from a recording surface of a disciform recording medium. In this method, data to be recorded on the recording surface is divided into a plurality of data blocks to be consecutively dealt with. Next, allocation information for designating each location of the plurality of data blocks is generated such that a second data block next to a first data block included in the plurality of data blocks is located to keep a predetermined interval from a location of the first data block.

Abstract: A data allocation control method is applicable to a data recording apparatus for writing and/or reading data to/from a recording surface of a disciform recording medium. In this method, data to be recorded on the recording surface is divided into a plurality of data blocks to be consecutively dealt with. Next, allocation information for designating each location of the plurality of data blocks is generated such that a second data block next to a first data block included in the plurality of data blocks is located to keep a predetermined interval from a location of the first data block.

Abstract: A method and a system for displaying multimedia data including video data. A display of video data and related information are controlled according to a movement of a pointing selection marker, a type of related information, or a distribution of pointing selection possible regions over frames of video data. Linked related information can be displayed in synchronization with a progress of a display of the video data. Information indicating a presence/absence of pointing selection possible region for currently displayed video data can also be displayed. A useful information can be obtained by collecting a statistical information on the desired positions specified by the user's pointing selection inputs. Each frame of video data can be partitioned and related information can be provided in correspondence to partitioned parts of each frame.

Abstract: A real time stream server using a disk device data restoration scheme, capable of shortening a restoration time by maximally utilizing the available stream resources, while providing the same service as in a case of normal operation, without setting any limitation on a new stream connection request during the restoration of lost data of a disabled disk device on a spare disk. The operations of the real time stream server is controlled by using normal streams for data transfer and restoration streams for data restoration, where as many stream resources as necessary are allocated to the normal streams first, and then at least a part of remaining stream resources are allocated to the restoration streams.

Abstract: The system and method store data into disk devices without loss of data, even when write requests having time limits are concentrated on a specific disk. When a write request for a given disk device is issued, if it is determined that some of this write request and other access requests having time limits for this disk device would not be executed within the respective time limits, the system writes the data temporarily into another disk device.

Abstract: A real time stream server capable of realizing a supply of a plurality of real time stream data with different data rates by a scheduling scheme using constant time-slot interval and transfer start timing period. A number of unit streams to be used and a block transfer time for each real time stream data are determined according to a data rate of each real time stream data. Each real time stream data is divided into a plurality of blocks, each block being in a size to be transferred within the block transfer time, and the blocks are sequentially distributed among the unit streams to be used. The blocks of each unit stream data are sequentially stored into a plurality of disk devices.

Abstract: A computer system monitors inter-process communications and performs a synchronous (global) checkpointing for processes that belong to a checkpoint group. The system also performs a local checkpointing at respectively arbitrary times within each process. When a fault occurs, a validity of each checkpoint is examined in accordance with monitoring results of inter-process communications related to the fault process. If the most recent checkpoint of the fault process is valid, only the fault process is rolled back. If it is invalid, all processes of the checkpoint group are rolled back to the global checkpoint, or each of the processes are rolled back to each optimum (valid) checkpoint.

Abstract: A continuous data server capable of reducing a cost for issuing control commands from a central control device to data memory control devices and communication control devices. The central control device issues a control command for each data memory control device and a control command for each communication control device collectively as a single control command set. Alternatively, the central control device issues control commands for the data memory control devices collectively as a single first control command set, and control commands for the communication control devices collectively as a single second control command set, through separately provided communication paths. When the continuous data are striped over data memory devices, the central control device can issue a common control command for all the data memory control devices.

Abstract: An archiving device with a plurality of drive devices for reading out a plurality of data constituting one data file from a plurality of removable recording media in parallel. A recording media loading/unloading device selectively loads/unloads the removable recording media to/from the drive devices. A control device controls the media loading/unloading operations by the recording media loading/unloading device and data reading operations by the drive devices according to a reading request for a desired data file so as to selectively use the drive devices in reading the desired data file from the removable recording media.

Abstract: A method and an apparatus for controlling a continuous data server, capable of dealing with a fault in the control device without affecting operations of the continuous data server, by using a plurality of control devices. One control devices is operated as a master control device for actually controlling operations of the continuous data server, while at least one control device other than the master control device is operated as a slave control device for monitoring the master control device and taking over a function of the master control device when a fault is detected in the master control device.