Abstract: A probabilistic detector is utilized to query a database. Utilization of a probabilistic detector provides assurance with 100 per cent probability that a search expression in the query is not in the database index. The probabilistic detector is implemented in the form of a Bloom filter. The probabilistic detector is created by hashing expressions in the database index and mapping the resulting hash values into the probabilistic detector. Upon receiving a query, expressions of the query are hashed. The probabilistic detector is queried using these hash values. If the results of querying the probabilistic detector indicate that searched for information may be in the database, the database is not queried. If the results of querying the probabilistic detector indicate that the information may be in the database, the database is queried for the information using the original query. This technique is advantageous in mitigating detrimental effects of denial of service attacks.

Abstract: The vulnerable interval between the occurrence of a localized or spot failure and the occurrence of a detectable disk failure is reduced by providing redundancy within a single disk. Sectors of the disk may be grouped into independent sets. Error-correcting or erasure-correcting codes may be applied across groups of sectors where the maximum number of failures prior to detectable disk failure is expected to be small. It is desirable to place all sectors in adjacent tracks in different redundancy groups. This provides a lower bound on the number of redundancy groups needed.

Abstract: Nodal pattern configuration is described, including generating successive values at a source node, processing the successive values using a plurality of intermediate nodes, sending the processed values from a node in the plurality of intermediate nodes to a destination node, and configuring the plurality of intermediate nodes such that each node of the plurality of intermediate nodes, concurrently performs at least two actions. Also, nodal pattern configuration includes generating a series of data blocks at a source node, processing data blocks from the series of data blocks using a plurality of intermediate nodes in data communication with the source node, each node of the plurality of intermediate nodes being configured to concurrently perform at least two operations, and sending processed data blocks from the plurality of intermediate nodes to a destination node, the destination node being in data communication with the plurality of intermediate nodes.

Abstract: Evaluating content includes receiving content, analyzing the content for web spam using a content-based identification technique, and classifying the content according to the analysis. An index of analyzed contents may be created. A system for evaluating content includes a storage device configured to store data and a processor configured to analyze content using content-based identification techniques to determine whether web spam is present.

Abstract: The present invention finds candidate objects for remote differential compression. Objects are updated between two or more computing devices using remote differential compression (RDC) techniques such that required data transfers are minimized. An algorithm provides enhanced efficiencies for allowing the receiver to locate a set of objects that are similar to the object that needs to be transferred from the sender. Once this set of similar objects has been found, the receiver may reuse any chunks from these objects during the RDC algorithm.

Abstract: Evaluating content is described, including generating a data set using an attribute associated with the content, evaluating the data set using a statistical distribution to identify a class of statistical outliers, and analyzing a web page to determine whether it is part of the class of statistical outliers. A system includes a memory configured to store data, and a processor configured to generate a data set using an attribute associated with the content, evaluate the data set using a statistical distribution to identify a class of statistical outliers, and analyze a web page to determine whether it is part of the class of statistical outliers. Another technique includes crawling a set of web pages, evaluating the set of web pages to compute a statistical distribution, flagging an outlier page in the statistical distribution as web spam, and creating an index of the web pages and the outlier page for answering a query.

Abstract: A method detects similar objects in a collection of such objects by modification of a previous method in such a way that per-object memory requirements are reduced while false detections are avoided approximately as well as in the previous method. The modification includes (i) combining k samples of features into s supersamples, the value of k being reduced from the corresponding value used in the previous method; (ii) recording each supersample to b bits of precision, the value of b being reduced from the corresponding value used in the previous method; and (iii) requiring l matching supersamples in order to conclude that the two objects are sufficiently similar, the value of l being greater than the corresponding value required in the previous method. One application of the invention is in association with a web search engine query service to determine clusters of query results that are near-duplicate documents.