Abstract: A method for determining a flow of information within a plurality of documents is provided. The method may include receiving the plurality of documents with each document having document content and a document timestamp. Based on the documents, the method may include constructing an inferred document causality forest by determining causal edges of the inferred document causality forest based on the document contents and the document timestamps. The inferred document causality forest may indicate a temporal flow of information from at least one earliest causal document of the plurality of documents. Further, each causal edge may extend from a node for an antecedent document to a node for a subsequent document that has a similarity above a similarity threshold and a document timestamp of the antecedent document may be earlier in time than a document timestamp of the subsequent document.

Abstract: A method of determining matching between at least a first sample comprising a sequence of tokens A and a second sample comprising a sequence of tokens B may include, for monotonically decreasing values of n, performing operations including recording a subset SA of n-grams of A in a hash table LA, such that a value of each n-gram determines an index in LA and a location of each respective n-gram in A is recorded as the value in LA, recording a subset SB of n-grams of B in a hash table LB, such that a value of each n-gram determines an index in LB and a location of each respective n-gram in B is recorded as the value in LB, for each location L that is occupied in both LA and LB, examining a region in A centered on LA(L) and a region in B centered on LB(L), and reporting a largest matching region aligning LA(L) with LB(L) that does not include already-matched tokens in A or B and marking the largest matching region as matched.

Abstract: A method for identifying similarity between query samples and stored samples in an efficiently maintained reference library may include receiving a binary query sample and processing the binary query sample via operations including producing a query sample fingerprint from the binary query sample, scoring the query sample fingerprint with each previously stored fingerprint in the reference library to produce a matching score, and for each previously stored fingerprint for which the matching score meets or exceeds a predetermined threshold, reporting a corresponding reference sample unique identifier associated with the previously stored fingerprint and the matching score. Each previously stored fingerprint in the reference library has been determined, prior to storage, as not being duplicative of another fingerprint in the reference library.

Abstract: An apparatus for identifying related code variants or text samples includes processing circuitry configured to execute instructions for receiving query binary code, processing the query binary code to generate one or more query code fingerprints comprising compressed representations of respective functional components of the query binary code, generating token sequence n-grams of the fingerprints, hashing the n-grams, partitioning samples by length to compare selected samples based on length, and identifying similarity via dynamic decimation of token sequence n-grams.

Abstract: A method for identifying similarity between query samples and stored samples in an efficiently maintained reference library may include receiving a first threshold and a second threshold, receiving a plurality of binary reference samples, and processing each reference sample of the plurality of reference samples. The processing may include operations of assigning each reference sample a respective unique identifier, producing a reference sample fingerprint for each reference sample, and registering each respective unique identifier to reference sample fingerprint pair in a reference library.

Abstract: A method for identifying similarity between query samples and stored samples in an efficiently maintained reference library may include receiving a binary query sample and processing the binary query sample via operations including producing a query sample fingerprint from the binary query sample, scoring the query sample fingerprint with each previously stored fingerprint in the reference library to produce a matching score, and for each previously stored fingerprint for which the matching score meets or exceeds a predetermined threshold, reporting a corresponding reference sample unique identifier associated with the previously stored fingerprint and the matching score. Each previously stored fingerprint in the reference library has been determined, prior to storage, as not being duplicative of another fingerprint in the reference library.

Abstract: A method for identifying similarity between query samples and stored samples in an efficiently maintained reference library may include receiving a first threshold and a second threshold, receiving a plurality of binary reference samples, and processing each reference sample of the plurality of reference samples. The processing may include operations of assigning each reference sample a respective unique identifier, producing a reference sample fingerprint for each reference sample, and registering each respective unique identifier to reference sample fingerprint pair in a reference library.

Abstract: An apparatus for identifying related code variants or text samples includes processing circuitry configured to execute instructions for receiving query binary code, processing the query binary code to generate one or more query code fingerprints comprising compressed representations of respective functional components of the query binary code, generating token sequence n-grams of the fingerprints, hashing the n-grams, partitioning samples by length to compare selected samples based on length, and identifying similarity via dynamic decimation of token sequence n-grams.

Abstract: An apparatus for identifying related code variants or text samples includes processing circuitry configured to execute instructions for receiving query binary code, processing the query binary code to generate one or more query code fingerprints comprising compressed representations of respective functional components of the query binary code, generating token sequence n-grams of the fingerprints, hashing the n-grams, partitioning samples by length to compare selected samples based on length, and identifying similarity via dynamic decimation of token sequence n-grams.

Abstract: A method of determining matching between at least a first sample comprising a sequence of tokens A and a second sample comprising a sequence of tokens B may include, for monotonically decreasing values of n, performing operations including recording a subset SA of n-grams of A in a hash table LA, such that a value of each n-gram determines an index in LA and a location of each respective n-gram in A is recorded as the value in LA, recording a subset SB of n-grams of B in a hash table LB, such that a value of each n-gram determines an index in LB and a location of each respective n-gram in B is recorded as the value in LB, for each location L that is occupied in both LA and LB, examining a region in A centered on LA(L) and a region in B centered on LB(L), and reporting a largest matching region aligning LA(L) with LB(L) that does not include already-matched tokens in A or B and marking the largest matching region as matched.

Abstract: An apparatus for identifying related code variants may include processing circuitry configured to execute instructions for receiving query binary code, processing the query binary code to generate one or more query code fingerprints comprising compressed representations of respective functional components of the query binary code, comparing the one or more query code fingerprints to at least some reference code fingerprints stored in a database to determine a similarity measure between the one or more query code fingerprints and at least some of the reference code fingerprints, and preparing at least one report based on the similarity measure.

Abstract: An apparatus for identifying related code variants or text samples includes processing circuitry configured to execute instructions for receiving query binary code, processing the query binary code to generate one or more query code fingerprints comprising compressed representations of respective functional components of the query binary code, generating token sequence n-grams of the fingerprints, hashing the n-grams, partitioning samples by length to compare selected samples based on length, and identifying similarity via dynamic decimation of token sequence n-grams.

Abstract: An apparatus for identifying related code variants may include processing circuitry configured to execute instructions for receiving query binary code, processing the query binary code to generate one or more query code fingerprints comprising compressed representations of respective functional components of the query binary code, comparing the one or more query code fingerprints to at least some reference code fingerprints stored in a database to determine a similarity measure between the one or more query code fingerprints and at least some of the reference code fingerprints, and preparing at least one report based on the similarity measure.

Abstract: An apparatus is described which detects the presence or absence of coherent light and provides an estimate of the coherent light's wavelength. The apparatus employs a common-path "polarization interferometer" in which the two linear polarization paths act as interferometer legs. Electro-optic modulation is used to effect periodic differential path length changes in the interferometer. The apparatus performs synchronous time-integrating detection on the light emerging from the interferometer to measure coherent contributions in the presence of obscuring incoherent light.

Abstract: An outer product shearing interferometer for an optical source of one-dimensional extent which provides interference between every two points on the source. The interferometer comprises an input plane containing the source, an output plane for observing the outer product, a hologram which imparts the sum of two contributions whose phases are bilinear functions of the spatial coordinates, a two-dimensional Fourier transform system which illuminates the hologram with the transform of light from the input plane, and a one-dimensional Fourier transform system which takes light from the hologram and illuminates the output plane.

Abstract: An outer product shearing interferometer for an optical source of one-dimensional extent which provides simultaneous interference between every two points on the source. The interferometer comprises an input plane containing the source, an output plane for observing the outer product, an imaging system between the two planes, and a mask positioned in the transform plane of the imaging system and having slits arranged to effect the desired outer product. The desired outer product results from a simultaneous application of many lateral shears instead of only one at a time.

Abstract: An apparatus is described which performs real time spectrum analysis of large bandwidth radio frequency signals. The apparatus allows the simultaneous monitoring of all frequencies within the band of interest, and operates in the presence of multiple frequencies.

Abstract: An apparatus is described which performs optical processing on electrical signals to calculate the triple product integral in a manner which accommodates high bandwidth signals, which processes were formerly possible only in mechanically unstable designs.

Abstract: An apparatus is described which performs acoustooptical signal processing functions with incoherent light, which procedures were formerly possible only with coherent light devices. Specific embodiments include an optical excisor, i.e., a programmable filter; a multichannel radiometer, i.e., an apparatus which estimates the power spectrum of a signal accompanied by noise; and an ambiguity processor, i.e., a time versus frequency cross correlator.

Abstract: Common path time and frequency domain optical adaptive linear predictors are disclosed, characterized by wide bandwidth operation for use in channel equalization, source redundancy removal, speech encoding, and other areas. The predictors are noninterferometric, avoiding the instability of such processors in the prior art.