摘要:
The present invention provides an index structure for managing weighted-sequences in large databases. A weighted-sequence is defined as a two-dimensional structure in which each element in the sequence is associated with a weight. A series of network events, for instance, is a weighted-sequence because each event is associated with a timestamp. Querying a large sequence database by events' occurrence patterns is a first step towards understanding the temporal causal relationships among the events. The index structure proposed herein enables the efficient retrieval from the database of all subsequences (contiguous and non-contiguous) that match a given query sequence both by events and by weights. The index structure also takes into consideration the nonuniform frequency distribution of events in the sequence data.
摘要:
Disclosed are a method, information processing system, and a computer readable medium for managing documents. The method includes analyzing a plurality of hierarchical markup documents, wherein each hierarchical markup document is representable by a hierarchical tree structure. A shared hierarchical markup document associated with the plurality of hierarchical markup documents is generated based on the analyzing. Each hierarchical markup document in the plurality of hierarchical markup documents is compared with the shared hierarchical document. A plurality of difference hierarchical markup documents is generated based on the comparing.
摘要:
A method, system and computer program product for confirming the validity of data returned from a data store. A data store contains a primary data set encrypted using a first encryption and a secondary data set using a second encryption. The secondary data set is a subset of the primary data set. A client issues a substantive query against the data store to retrieve a primary data result belonging to the primary data set. A query interface issues at least one validating query against the data store. Each validating query returns a secondary data result belonging to the secondary data set. The query interface receives the secondary data result and provides a data invalid notification if data satisfying the substantive query included in an unencrypted form of the secondary data result is not contained in an unencrypted form of the primary data result.
摘要:
Most recent research of scalable inductive learning on very large streaming dataset focuses on eliminating memory constraints and reducing the number of sequential data scans. However, state-of-the-art algorithms still require multiple scans over the data set and use sophisticated control mechanisms and data structures. There is discussed herein a general inductive learning framework that scans the dataset exactly once. Then, there is proposed an extension based on Hoeffding's inequality that scans the dataset less than once. The proposed frameworks are applicable to a wide range of inductive learners.
摘要:
A system and method for learning models from scarce and/or skewed training data includes partitioning a data stream into a sequence of time windows. A most likely current class distribution to classify portions of the data stream is determined based on observing training data in a current time window and based on concept drift probability patterns using historical information.
摘要:
A computer implemented method, apparatus, and computer usable program code for processing multi-way stream correlations. Stream data are received for correlation. A task is formed for continuously partitioning a multi-way stream correlation workload into smaller workload pieces. Each of the smaller workload pieces may be processed by a single host. The stream data are sent to different hosts for correlation processing.
摘要:
Load shedding schemes for mining data streams. A scoring function is used to rank the importance of stream elements, and those elements with high importance are investigated. In the context of not knowing the exact feature values of a data stream, the use of a Markov model is proposed herein for predicting the feature distribution of a data stream. Based on the predicted feature distribution, one can make classification decisions to maximize the expected benefits. In addition, there is proposed herein the employment of a quality of decision (QoD) metric to measure the level of uncertainty in decisions and to guide load shedding. A load shedding scheme such as presented herein assigns available resources to multiple data streams to maximize the quality of classification decisions. Furthermore, such a load shedding scheme is able to learn and adapt to changing data characteristics in the data streams.
摘要:
A system for combining ranking and clustering in a query. Bit vectors are intersected on Boolean attributes resulting in a vector. Two summary grids are constructed by intersecting bit vectors on clustering and ranking attributes. The vector is intersected with each summary grid to obtain a filtered clustering and ranking grid. An algorithm is applied on the clustering grid to obtain clusters. Vectors associated with buckets in the clusters are intersected resulting in one vector for each cluster. The vector corresponding to each cluster is intersected with the ranking grid to obtain a modified grid. Buckets are pruned according to bounds of each bucket in the modified grid and a predetermined number to obtain candidate buckets containing the predetermined number of data. The data are retrieved and a ranking score is calculated. The top predetermined number of data are sorted according to ranking scores and a result is returned.
摘要:
A dynamic rule classifier for mining a data stream includes at least one window for viewing data contained in the data stream and a set of rules for mining the data. Rules are added and the set of rules are updated by algorithms when an drift in a concept within the data occurs, causing unacceptable drops in classification accuracy. The dynamic rule classifier is also implemented as a method and a computer program product.
摘要:
A method, apparatus, and computer program product for querying data in a database. An ontology is associated with the data in the database. A query containing a query predicate is received. The query predicate is expanded using implications from the ontology to form a modified query. The modified query is rewritten to include subsumption checking.