Abstract: Methods and systems are disclosed for detection of agents such as pathogens or toxic substances and, in particular, to methods and systems for determining the most important background constituents to suppress in a sample, e.g., in a bulk aerosol sample, in order to reduce the probability of false alarms and improve the level of detection of potentially harmful airborne agents.

Abstract: Method of identifying invalid digital signatures involving batch verification by receiving digital messages, digital signatures, and signer identifiers, computing Z0 as a function of the received information, and determining if the digital signatures are valid. If so, stopping. If not, assigning a signature identifier to each digital signature, setting w equal to 1, computing Zw as a function of the received information and signature identifiers, and searching for a multiplicative relationship amongst Z0, Z1, . . . , Zw. If one is found then determining the invalid digital signatures from the multiplicative relationship and stopping. Otherwise, incrementing w and returning to the step of computing for additional processing if desired.

Abstract: A passive skin detection system includes a main body which houses a collection optics system having an image splitting device, a visible light filter mechanism having a plurality of narrow band filters and an image capture system. The image capture system stores visible light data as a plurality of digital images formed from a plurality of pixels. Each of the plurality of digital images is associated with visible light passed through a respective one of the plurality of narrow band filters. An image processing system, operatively connected to the image capture system, compares relative intensities of each of the plurality of digital images to identify one or more of the plurality of pixels having an absorption bandwidth indicating a presence of skin. The processing system determines whether a person, identified by his skin, is present in any of the images captured by the detection system.

Abstract: Methods and systems are disclosed for detection of agents such as pathogens or toxic substances and, in particular, to methods and systems for determining the most important background constituents to suppress in a sample, e.g., in a bulk aerosol sample, in order to reduce the probability of false alarms and improve the level of detection of potentially harmful airborne agents.

Abstract: Methods and systems are disclosed for selecting a set of interrogation wavelengths from spectral data, the method including the steps of performing a principal coordinate transformation on the spectral data, choosing an objective function which describes the efficiency of the transformation in separating the class of agents from the class of interferents, rank ordering the interrogation wavelengths according to said objective function, and choosing the set of wavelengths with the highest rank. In one preferred embodiment, the objective function is the smallest spectral angle between the class of agents and the class of interferents.

Abstract: The present invention generally provides systems and methods for detection of agents of interest in a bulk quantity of matter, which also contains clutter and other constituents that typically interfere with the detection of one or more agents of interest. A detection system of the invention generally contains a collection subsystem for obtaining a bulk sample, an interrogation subsystem for generating one or more analytical signals representative of the composition of the bulk sample, and an analytical subsystem according to the teachings of the invention that implements the methods and algorithms of the invention for analyzing the sample analytical signals to determine whether one or more agents of interest are present, e.g., at quantities above a certain threshold, in the bulk sample.

Abstract: The present invention generally provides methods and systems for characterizing texts, for example, for identifying textual documents by language, topic, author, or other attributes. In some embodiments, a method of the invention can include creating an n-gram frequency spectrum for a document under analysis, preferably selecting a subset of the n-gram frequency spectrum, transforming the n-gram frequency spectrum into principal component space, and identifying one or more attributes of the document according to its similarity to (or distinction from) reference documents in the principal component space.

Abstract: A system for obtaining frequency domain interferometric super-resolution of a target scatterer, having a first and a second coherent transceivers, a mutual coherent sub-system and an estimation system. The first and second coherent transceivers are operative to produce a plurality of first and second sampling signals separated from each other by a predetermined frequency difference within the first and second sub-band, respectively. The mutual coherent sub-system is coupled to the first and second coherent transceivers to receive phase and amplitude of the first and second sampling signals, so as to evaluate an ambiguous range estimate from a pair of the first and second sampling signals and an unambiguous range estimate from a pair of the first and/or second sampling signals.

Abstract: The present invention generally provides systems and methods for distribution of radiation among a plurality of optical channels, each of which can include a non-linear optical element. An optical system of the invention can include a source for generating radiation and an optical time-division multiplexer that can deflect, at any given time interval, the radiation into one of a plurality of optical channels.

Abstract: The present invention generally provides systems and methods for distribution of radiation among a plurality of optical channels, each of which can include a non-linear optical element. An optical system of the invention can include a source for generating radiation and an optical time-division multiplexer that can deflect, at any given time interval, the radiation into one of a plurality of optical channels.

Abstract: A spinal implant for rigid fixation of at least two vertebrae of a pine has at least one support member configured for attachment to the vertebrae and is comprised of a bio-compatible polymer composite. A plurality of fasteners attach the support members to the vertebrae. A predefined standard selection of such bio-compatible implant components Ore provided so as to define support members which conform to the specific anatomical structure of the patient's spine without being modified.

Abstract: A system (30) for outputting digital data stored in a memory of a computer (12) in accordance with the invention includes a graphics display processor (20), coupled to the memory, for processing the digital data stored in the memory to produce at least one serial data stream including clock information, which is a function of a clock signal representative of a rate at which the at least one display formatted serial data stream is outputted, and display information for use in controlling a video monitor; a video channel (24), coupled to the display processor, for outputting the at least one serial data stream produced by the graphics display processor; a data processing memory (52); and a data processing system (40, 44 and 50) for processing the at least one serial data stream in response to the clock information and for removing at least the display information and controlling storing of the at least one of the at least one serial data stream with the display information removed which contains the digital dat

Abstract: An improved interferometer measuring system that corrects for errors in the determination of the position of a measurement reflector along a measurement path due to the presence of an atmosphere (e.g. atmospheric turbulence) along the path is disclosed. The system includes a two-wavelength interferometer for measuring the atmosphere and a basic length interferometer for a basic measurement of a change in position of the measurement reflector. A calibration procedure for correcting the basic measurements made by the basic length interferometer uses first and second correction coefficients related to the average refractivity of the atmosphere and the change in the refractivity of the atmosphere, respectively. The coefficients can be determined by interferometric measurements or from a combination of interferometric measurements and data from an atmospheric sensor(s), including a humidity sensor.

Abstract: A system (30) for outputting digital data stored in a memory of a computer (12) in accordance with the invention includes a graphics display processor (20), coupled to the memory, for processing the digital data stored in the memory to produce at least one serial data stream including clock information, which is a function of a clock signal representative of a rate at which the at least one display formatted serial data stream is outputted, and display information for use in controlling a video monitor; a video channel (24), coupled to the display processor, for outputting the at least one serial data stream produced by the graphics display processor; a data processing memory (52); and a data processing system (40, 44 and 50) for processing the at least one serial data stream in response to the clock information and for removing at least the display information and controlling storing of the at least one of the at least one serial data stream with the display information removed which contains the digital dat

Abstract: An improved interferometric measuring system that includes a system for measuring a phase difference between two coherent beams oscillating at substantially the same frequency, and including a phase modulator disposed into optical communication with one of the coherent beams and being adapted to generate a phase modulated beam signal. A beam combiner combines the phase modulated beam signal with the second one of the coherent beams to generate a combined beam signal. A detector element measures the intensity of the combined beam signal and a date processor analyzes the intensity to determine from the harmonic components of the combined beam signal the phase difference between the two coherent beams.

Abstract: A fluid sampling device has an elongate tube formed substantially of polyphenylene sulfide. A top end fitting is formed to the top end of the tube and is configured for connection to a tether. A bottom end fitting is similarly formed to the bottom end of the tube and has a check valve formed therein for allowing fluid to flow therethrough into the tube when the fluid sampling device is lowered into a fluid and for inhibiting fluid flow therethrough out of the tube when the tube is being raised and handled. The tube, top end fitting, bottom end fitting, and check valve are all formed of an inert material so as to maintain the integrity of the fluid sample collected. The use of polyphenylene sulfide provides a lightweight fluid sampling device which is durable enough to resist damage during routine handling and use.

Abstract: An improved interferometric measuring system wherein the system projects a first beam of light at a first measurement wavelength along a reference path to a reference reflector and a second beam of light at a second measurement wavelength along a measurement path to a measurement reflector, and determines a change in position of the measurement reflector from an interference pattern produced between a first light beam reflected from the reference reflector and a second light beam reflected from the measurement reflector, and wherein the system can measure atmospheric disturbances along the measurement path, concurrently with measuring a change in the position of the measurement reflector.

Abstract: An improved interferometric measuring system wherein the system projects a first beam of light at a first measurement wavelength along a reference path to a reference reflector and a second beam of light at a second measurement wavelength along a measurement path to a measurement reflector, and determines a change in position of the measurement reflector from an interference pattern produced between a first light beam reflected from the reference reflector and a second light beam reflected from the measurement reflector, and wherein the system can measure atmospheric disturbances along the measurement path, concurrently with measuring a change in the position of the measurement reflector.

Abstract: A pebble-bed evaporator and superheater assembly includes a tubular pressure shell with internal baffles, the latter including a plurality of apertures therein for passage of gas therethrough. Contained within the shell are heater elements and pebble elements which store heat and transfer the same to liquified gas which is vaporized and flows through the shell whereby the gas supplied to the shell and is heated to a predetermined elevated temperature above its input temperature. The heated gas output of the shell flows to a mixer unit connected to the shell and the mixed gas flows out of the mixer. Connected to the mixer is a supply of liquified gas to cool the high temperature gas entering the mixer from the shell such that the temperature of the gas exiting the mixer is below the temperature of the heated gas exiting the shell. In this way the temperature of the gas exiting the mixer is controlled to the desired level.

Abstract: A multidimensional optical storage medium is provided for storing a plurality of holographic images representative of data. An interrogation network generates a search argument including a target data field to be simultaneously searched for over at least a segment of the optical storage medium. The interrogation network couples the search argument into the optical storage medium and extracts a set of address fields at which data fields in the storage medium that match the target data field of the search argument are stored.