Abstract: A method of data placement and control in a block-divided distributed disk array is provided. At first, data to store is divided into logical blocks, and each of the divided logical blocks is further divided into a plurality of data blocks. Then, a parity block is created through performing an XOR operation on the data blocks of each logical block in a unit of a strip, and the parity block is arranged at the first block of a strip unit. Then, parity blocks are arranged at a next block of a previous logical block's the last data block through a left/right shifting for uniformly arranging the parity blocks through out all disks in order to fill an empty block between the logical blocks.

Abstract: A cache coherency maintenance system and method of a user file manager in an object-based storage system are provided. According to the cache coherence maintenance system and method, by maintaining the coherency of a writeback cache based on time using a timer, metadata and data information are efficiently managed. Accordingly, even when accesses by users increase, the cost of maintaining the coherency of the cache is distributed to respective user file managers. In this way the performance of the entire object-based storage system is enhanced and the consistency and efficiency of information increase.

Abstract: Provided is a stream data processing system and method for avoiding duplication of data process. The system including: an evaluation result storing unit for updating and storing a query condition evaluation result; a window evaluating unit for performing window evaluation; a data separating unit for separating data into new data and duplication input data; a reuse result extracting unit for receiving duplication input data from the data separating unit and extracting a query condition evaluation result; a query condition evaluating unit for receiving new data from the data separating unit, performing query condition evaluation and creating a query condition evaluation result; and a result organizing unit for receiving the query condition evaluation result, merging, outputting and transmitting the query condition evaluation result to the evaluation result storing unit.

Abstract: Provided are a system and a method for processing integrated queries against an input data stream and data stored in a database using trigger. The system for processing an integrated query against an input data stream and data stored in a database using a trigger, including: a data stream manager for managing a continuously inputted data stream; a trigger result manager for registering a trigger in a database which interworks with the trigger result manager and forming a set of results that are obtained by executing the registered trigger to thereby provide the set of results in real time; and an executer for processing an integrated query against the data stream from the data stream manager and data stored in the database, wherein the integrated query is processed by referring to the set of results from the trigger result manager for the data stored in the database.

Abstract: A packet detecting device used in a receiver employing PCI Express protocol is disclosed. The packet detecting device includes: a physical layer packet detecting unit for detecting a physical layer packet from a PCI express packet received and parallelized to 16 bit data through a physical deserializer; a descrambling unit for descrambling a physical layer packet from a PCI express packet received and parallelized to 16 bit data through a physical deserializer; a data link layer packet detecting unit for detecting a data link layer packet from a descrambled packet outputted from the descrambling unit; and a transaction layer packet detecting unit for detecting a transaction layer packet from a descrambled packet outputted from the descrambling unit.

Abstract: Provided is an apparatus and a method for creating and managing Transmission Control Protocol (TCP) transmission information based on a TCP Offload Engine (TOE). The apparatus includes: a TCP transmission processing unit for receiving a data transmission request from a predetermined network program, creating transmission information and deleting the transmission information; a TCP reception processing unit for receiving a reception command of the data, creating and managing the reception information; a transmission information region managing unit for allocating memory regions for storing the transmission information according to a command of the TCP transmission processing unit, creating an identification (ID) of each region, and managing a deleting process; and a storing unit for storing and deleting the transmission information according to control of the TCP transmission processing unit.

Abstract: An apparatus for searching a socket ID of a received packet in a transmission control protocol (TCP) and a user datagram protocol (UDP) is provided. The apparatus includes: a master managing unit for analyzing command information from a processor, transferring a command to a branch table managing unit and a tree table managing unit, receiving results from the branch table managing unit and the tree table managing unit, and reporting the received results to the processor; a branch table managing unit for receiving a command from the mater managing unit and managing a branch table; and a tree table managing unit for managing a binary tree.

Abstract: A fractional caching method and an adaptive contents transmitting method using the same are provided. The fractional caching method includes the steps of setting up a divided location for dividing a certain object into two parts, receiving an evict request for acquiring a space in the inside of the cache, when the evict request is transmitted, dividing a plurality of objects stored in the cache into a prefix-Object located in the head of the object and a suffix-Object located in the tail of the object from the divided location, and removing only the suffix-Object of each object, wherein the divided location is set up at a size rate that a size of the prefix-Object is in inverse proportion to the number of the destination types.

Abstract: A file level striping method adds an option for indicating whether or not to support file level striping to a file creation interface in a file system, extends an inode structure to include a last disk ID field, initializes the last disk ID when the file is created in the file system, allocates a physical block based on the last disk ID when the physical block allocation is requested at the time of file I/O request in the file system, and modifies the last disk ID value to reflect the physical block allocation made by a volume manager. An apparatus using the file level striping method includes a number of disks for storing information actually, the volume manager for logically grouping a number of disks and a file system for creating files on said logical volume and performing I/O operations.

Abstract: A cache consistency maintenance procedure to select one of a detection-based cache consistency maintenance procedure optimized for record-based locking and an avoidance-based consistency-based maintenance procedure optimized for table and block-based locking. To support the characteristic of DBMS in which table locking and record locking are consistent to access the same table, the two kinds of the consistency maintenance policies for the same block are processed by a single buffer load process and the two kinds of the consistency maintenance policies are consistent with each other to provide better configuration and performance.

Abstract: An efficient snapshot technique based on a mapping for a large logical volume shared in multiple hosts. According to the present invention, problems of time delays in a conventional snapshot technique is solved by employing a FAB and an SSB, which are bits representing whether a COW operation is carried out to a mapping entry. In other words, the present invention solves the problems of delaying a write operation of corresponding volume, which is simultaneously executed when a snapshot is created, until the snapshot creation is completed.

Abstract: Disclosed a method of designing a watermark having the power spectral density optimized so that the detection performance can be improved by employing the whitening filtered detection after the Wiener attack. The power spectral density of the watermark is designed using an optimization method that can improve the entire detection performance by reflecting the gain of the whitening filter after the Wiener attack. A higher detection gain is obtained using the whitening filter after the Wiener attack, and the expected value of the difference between test statistics of the two hypotheses that the watermark exists and the watermark does not exist, respectively, is maximized to optimize the detection performance. Regarding the expected value of the difference between the test statistics as an objective function, the power spectral density of the watermark, which corresponds to a maximum differentiated value of the power spectral density of the watermark using the Lagrange multiplier method, is obtained.

Abstract: An object-based storage device with a low process load and a control method thereof are provided. The object-based storage device includes: a storage unit; a temporary storage unit; a transmission unit; a first control unit; and a second control unit. Particularly, the temporary storage unit and the transmission unit are provided separate from the main storage unit and the system bus, and these separately provided temporary storage unit and transmission unit allow a direct data transmission, which attributes to a reduction in a process load and a burden on the system bus.

Abstract: Provided are a hardware device and a method for creating and managing socket information serving as a connection with a network protocol hierarchy in a network application program. The hardware device includes a TCP transmission processor for processing commands on requests for creating and eliminating a socket of a predetermined network program in response to the requests for creating and eliminating a socket, a TCP reception processor for creating a search signal for a corresponding socket identification when a new packet is received, a socket management unit for creating and eliminating a socket ID upon a command from the TCP transmission processor, and searching the socket ID and providing the socket ID to the TCP transmission processor upon a command from the TCP reception processor, and a memory unit for storing the socket information, and providing the socket information to the TCP reception processor.

Abstract: A device for effectively and economically receiving a packet by eliminating temporary memory and a memory controller. The apparatus includes an inspection logic circuit for inspecting data units as soon as they arrive in order to find an error included in the packet and generating control signals according to a result of inspecting a data unit; a multiplexer for receiving data units and distributing the received data units as soon as the data units have arrived; and FIFO memories for receiving the data unit, storing the data unit in a corresponding one of FIFO memories and either deleting or completing storing data units according to the control signals from the inspection logic circuit. The present invention can reduce manufacturing cost of the device by eliminating a temporary memory and a memory controller for the temporary memory and can also reduce processing time.

Abstract: Disclosed is a method for embedding and extracting a spatial domain blind watermark using a sample expansion. The sample expansion method using a sample expansion coefficient is introduced to basically improve a common disadvantage of the conventional watermarking method based on the patchwork method, for instance, the watermark is not robust against a compression attack such as JPEG. By applying the sample expansion to a sample group, the embedded watermark comes to contain a low frequency component more larger than ever, so that radio frequency component decreases as much. Thus, although the radio frequency component of the watermark is damaged by the image compression such as JPEG, it is possible to relatively reduce the damage of the watermark. Also, an adaptive watermark embedding method can be considered such that the embedded watermark value is proportional to an average value of the pixel.

Abstract: A method for file deletion and recovery against system failures in a database management system comprising steps of deleting files listed in a pending action list during a transaction commit process, writing a non-atomic file deletion as an atomic operation into a log and recovering uncompleted file deletion during restart recovery by using the log is disclosed. When system failures occur during file deletion in a database management system, resources of which releasing is interrupted by failures are released perfectly through recovery step, so it is advantageous in that coherency of data is maintained and efficiency of storage device arises.

Abstract: Disclosed is an XML database duplicating apparatus and method capable of providing an effective application service without interruption at a low cost in the diverse Internet environments by copying an XML document of a database system mounting an XML processing technique to another remote server. When the XML document stored in a database of the original server is copied to databases of copied servers, the structure and attribute information included in the XML document are maintained as they are, and thus the respective copied servers can support the searches based on the contents and the attribute provided by an XML query language and disperse users' queries concentrated to the original server to the respective copied servers, so that the service request for application programs can be processed.

Abstract: The present invention is a data transfer protocol control system with a host bus interface that includes a transmitting/receiving command DMA, a transmitting data DMA and a receiving data DMA for controlling data transfer protocol with a host bus interface considering characteristic, usage frequency, simultaneous processing functions of the command DMA and the data DMAs. A host interface bus is efficiently used and bus usage ratio is distributed properly to support transfer flow properly and improve the entire system performance.

Abstract: In a first-in first-out memory circuit using a standard cell library memory, a memory block includes N number of memories (N>1). A read pointer designates read addresses of the N number of memories. A write pointer designates write addresses of the N number of memories. A memory controller selects one from the N number of memories based on the read/write addresses, generates n number of read/write clock signals by demultiplying a clock signal by n (n=N, n>1) and sends the n number of read/write clock signals having a 1/n cycle difference to the N number of memories thereby inputting/outputting data.