摘要:
The present invention relates to a computer-implemented technique for drawing directed graphs providing reduced crossings and improved picture quality. An edge list description provided by a user is processed to produce a ranking of all nodes that minimizes the weighted sum of all edges, an edge cost being the product of its weight and length. Nodes within a ranking are then positioned to reduce edge crossings using a heuristic based on node positions in adjacent ranks. Such heuristic uses a generalized median as a weighting function plus node transposition to avoid senseless edge crossings before proceeding to a next rank. Nodes are then positioned to minimize the weighted sum of horizontal distances among connected nodes. Spline control points are then computed for interconnected nodes, and a code sequence for a drawing is generated.
摘要:
The present invention provides efficient window partitioning algorithms for entropy-encoding. The present invention enhances compression performance of entropy encoding based on the approach of modeling a dataset with the frequencies of its n-grams. The present invention may then employ approximation algorithms to compute good partitions in time O(s*log s) and O(s) respectively, for any data segment S with length s.
摘要:
The present invention provides efficient window partitioning algorithms for entropy-encoding. The present invention enhances compression performance of entropy encoding based on the approach of modeling a dataset with the frequencies of its n-grams. The present invention may then employ approximation algorithms to compute good partitions in time O(s*log s) and O(s) respectively, for any data segment S with length s.
摘要:
A preload library partitions certain files into segments and transforms the data of the files on a segment by segment basis, each independently of the other. The transformed segments are then stored as part of a transformed file, with each segment corresponding to a bag containing a chunk (of transformed data) and a gap which permits the chunks to grow when data of the segment is modified during a write operation. The bags are followed by a chunk map which contains metadata defining the compressed version of each segment. The preload library intercepts system calls from applications to the OC specifying access to specific segments of a transformed file. The preload library identifies the chunks corresponding to the specified segments, retrieves and reverses the transform on those chunks and passes the data to the application requesting it. For a system call to write data to certain segments, the data is modified and re-transformed by the library before being written back to disk. A preload library provides improved random access into transformed (e.g. compressed, encrypted, etc.) files.
摘要:
The present invention increases the efficiency of performing longest prefix matching operations by selecting a radix-encoded trie structure optimized with respect to memory cost. The structure is optimized by determining memory costs for retrie structures indexed on different numbers of high-order characters, and then selecting the structure corresponding to the lowest memory cost. The optimization improves performance in IP look-up operations as well as longest-prefix matching operations performed on general alphabets.
摘要:
The present invention is a method and system for buffering and replaying a segment of a voice or data transmission. A connection is established between two end nodes in the network. At an intermediate node in the network between the end nodes, a predetermined segment of the data is maintained in a memory as a buffer. Upon receiving a request from one of the end nodes to replay the segment, that segment is replayed and transmitted to the requesting node. The request may be made by a user at one of the end nodes, or may be made automatically after detecting corrupt data. Because the buffering module is in the network, it need not be incorporated in premises or mobile equipment. Because the buffering module is remote from the requesting end node, the replayed data does not contain errors introduced in the original data between the buffering module and the requesting end node.
摘要:
By checkpointing and restoring a user application process, that includes a volatile state and a persistent state, recovery of an application process from the checkpoint position is possible. Specifically, a volatile state is checkpointed in a checkpoint position. Next, the persistent state is monitored to detect a file operation following a checkpoint position that will modify the persistent state. Then, portions of the persistent state are checkpointed if a modification of the persistent state is about to be performed. Then, a recovery to the checkpoint position can be performed such that modifications to the persistent state since the checkpoint position are undone. This allows for resumption of the user application process from the checkpoint position.
摘要:
A system and method for selective regression testing of a software system that determines which test units of a test suite must be re-run after a modification to the software system. The entities which are covered by each test unit are identified. When the software system is modified the entities which were changed by the modification are identified. The test units which need to be re-run are determined by analyzing the change information and the coverage information to select those test units that cover changed entities.
摘要:
A preload library partitions certain files into segments and transforms the data of the files on a segment by segment basis, each independently of the other. The transformed segments are then stored as part of a transformed file, with each segment corresponding to a bag containing a chunk (of transformed data) and a gap which permits the chunks to grow when data of the segment is modified during a write operation. The bags are followed by a chunk map which contains metadata defining the compressed version of each segment. The preload library intercepts system calls from applications to the OC specifying access to specific segments of a transformed file. The preload library identifies the chunks corresponding to the specified segments, retrieves and reverses the transform on those chunks and passes the data to the application requesting it. For a system call to write data to certain segments, the data is modified and re-transformed by the library before being written back to disk. A preload library provides improved random access into transformed (e.g. compressed, encrypted, etc.) files.
摘要:
A relational dependency transform is introduced as a way to exploit information redundancy in conditioning data in a relational database for better compressibility. An optimum relational dependency transform of the relational database is first computed. Fields of the relational database are then sorted topologically based on a weighted, directed graph having nodes representing predictor and predictee fields. For each predictee field in the topological order, a transformed field is then computed via the relationship between predictor and predictee in the optimum relational dependency transform.