Abstract: Changes, increase or decrease, in the body fluid are passively detected by using a single pixel, non-linear blind de-mixing procedure, which can be extended to general biomedical measurement and diagnosis instruments. More specifically, the single pixel, non-linear blind de-mixing procedure in applied on the hot spots of rheumatic arthritis or breast cancer detection problem using passive two-color infrared imaging, as well as to passively detect blockages in the body fluid circulatory system that might be of importance for coronary artery bypass surgery, diabetes and deep vein thrombosis. Other applications of the mentioned algorithm include a pair of cameras for video, a pair of antennas for cell phones, and in situ data gathering or imaging using multiple mode fiber-optical sensing, as well as selective amplification hearing aids through two-ear binaural processing for de-noise echo cancellation and signal classification.

Abstract: The invention employs a group of LED devices as a light source for emitting light with different wavelengths towards the solar cell under test. A set of test signal data composed of mutually orthogonal test signals are used to power the LED devices to emit light. The solar cell, upon receiving light from the LED devices powered by the test signal data, generates detected values which are in turn converted into electric signals. A processor device is then used to separate component signals contributed by the respective LED devices from the signals and compare the component signals to the output power level corresponding to the test signal data and/or to the optical energy levels radiated from the respective LED devices, thereby obtaining the spectral response of the solar cell to the different wavelengths of light.

Abstract: Disclosed is a method of detecting at least one oscillatory fault in at least one positional slaving chain for at least one airfoil of an aircraft. The method involves estimating a reference position of the airfoil in the absence of a fault, and calculating a residual value based on the difference between the estimated reference position and the actual position measured by at least one sensor. The calculated residual value is compared with at least one predetermined threshold value to determine the number of successive and alternating overshoots of the predetermined threshold value by the residual value, and oscillatory fault is determined based on the determined number.

Abstract: A system capable of separating sound source signals with high precision while improving a convergence rate and convergence precision. A process of updating a current separation matrix Wk to a next separation matrix Wk+1 such that a next value J(Wk+1) of a cost function is closer to a minimum value J(W0) than a current value J(Wk) is iteratively performed. An update amount ?Wk of the separation matrix is increased as the current value J(Wk) of the cost function is increased and is decreased as a current gradient ?J(Wk)/?W of the cost function is rapid. On the basis of input signals x from a plurality of microphones Mi and an optimal separation matrix W0, it is possible to separate sound source signals y(=W0·x) with high precision while improving a convergence rate and convergence precision.

Abstract: Provided are an apparatus and method of separating, from a mixed signal, a sound source generated using a rhythm musical instrument based on characteristics of the rhythm musical instrument repeated in an aspect of time. The apparatus may include a separation unit to separate a plurality of mixed signals into a plurality of segments, a Nonnegative Matrix Partial Co-Factorization (NMPCF) analysis unit to perform an NMPCF analysis on the plurality of segments, and to obtain a plurality of entity matrices based on the analysis result, a target instrument signal separating unit to separate, from the mixed signals, a target instrument signal, by calculating an inner product between the plurality of entity matrices, and a signal association unit to associate the target instrument signals separated from each of the plurality of segments.

Abstract: A method is used for providing sensing data to a control system of a machine. The method may include providing a plurality of virtual sensors, each of which may have a model type, at least one input parameter, and at least one output parameter. The method may also include integrating the plurality of virtual sensors into a virtual sensor network; determining interdependencies among the plurality of virtual sensors; and obtaining operational information of the plurality of virtual sensors. Further, the method may include determining a first condition under which the virtual sensor network is unfit to provide one or more virtual sensor output parameter to the control system based on the determined interdependencies and the operational information; and presenting the determined first condition to the control system.

Abstract: A method and system for an interactive controller device comprising a two axis sensor in combination with one or more other sensors for hand-held devices operated in mid-air. A time sequence of measurements in three linearly independent directions is used to extract the angles of rotation around one or more distinct axes. A method is disclosed to approximately determine a transformation matrix, T, of a device orientation from a sequence of single vector measurements as a combination of rotations about specified axes. Calculated rotation angles can then be used to calculate changes in a controller or pointer position and a rate change thereof.

Abstract: A method is provided for de-embedding the S-parameter response of an electrical DUT embedded in an electrical network. The method comprises making first and second S-parameter measurements in the frequency domain at a port or measurement reference plane to the network containing the DUT. For the second measurement, a known impedance condition is created at the embedded location of the DUT. The first and second measurements are transformed to the time domain, and then gated to select portions of the time-domain-transformed responses that correspond to paths that include the DUT and known impedance condition, respectively. The gated time domain responses are then transformed back into the frequency domain, yielding first and second selected S-parameter measurement responses M1 and M2, respectively. A reflection S-parameter for the DUT is then determined as a function of the first and second selected S-parameter measurement responses and the known impedance condition.

Abstract: Tensor linear Laplacian discrimination for feature extraction is disclosed. One embodiment comprises generating a contextual distance based sample weight and class weight, calculating a within-class scatter using the at least one sample weight and a between-class scatter for multiple classes of data samples in a sample set using the class weight, performing a mode-k matrix unfolding on scatters and generating at least one orthogonal projection matrix.

Abstract: Chromatograms and mass spectra produced by an LC/MS system are analyzed by creating a two-dimensional data matrix of the spectral and chromatographic data. The two-dimensional matrix can be created by placing the spectra generated by the mass spectrometer portion of the LC/MS system in successive columns of the data matrix. In this way, the rows of the data matrix correspond to chromatographic data and the columns of the data matrix correspond to the spectra. A two-dimensional filter is specified and applied to the data matrix to enhance the ability of the system to detect peaks associated with ions. The two-dimensional filter is specified according to desired criteria. Rank-1 and rank-2 filters can be specified to improve computational efficiency. One method of applying the two-dimensional filter is through convolution of the data matrix with the two-dimensional filter to produce an output data matrix. Peaks corresponding to detected ions are identified in the output data matrix.

Abstract: An adaptive real-time analysis method for dynamic signals generated by rotary machines improves Vold-Kalman filtering order tracing technology to renew the algorithm logic so that on-line computation ability is achieved. Through signal simulation and practical engineering application to verify the availability, it shows that the output results are extremely accurate. As such, this method is advantaged to estimate the time-domain waveform of specific order signals for the operation of the rotary machines and to interpret the related physical phenomena. Moreover, this method can be applied for a digital signal processor (DSP) to obtain real-time and on-line computation of the order signals needed to be traced and to display the tracing time-domain waveform instantly.

Abstract: A system capable of reducing the influence of sound reverberation or reflection to improve sound-source separation accuracy. An original signal X(?,f) is separated from an observed signal Y(?,f) according to a first model and a second model to extract an unknown signal E(?,f). According to the first model, the original signal X(?,f) of the current frame f is represented as a combined signal of known signals S(?,f?m+1) (m=1 to M) that span a certain number M of current and previous frames. This enables extraction of the unknown signal E(?,f) without changing the window length while reducing the influence of reverberation or reflection of the known signal S(?,f) on the observed signal Y(?,f).

Abstract: Color measurements of color samples are estimated by a system and method wherein an area coverage of a color sample is computed, the color sample is printed, a color of the printed color sample, such as a set of reflectance values, is measured at a first temperature, and a color of the printed color sample is estimated at a second temperature lower than the first temperature, the estimation being based on the area coverage and a thermochromatic model which represents relationships between measured colors of printed color samples at the first and second temperatures.

Abstract: The spectral method for determining the concentrations of a substance in a mixture of any number of substances is defined by a chemical image having a plurality of pixels (520). The method includes steps of providing a spectrum for each of the n number of substances in the mixture (530), and obtaining the spectrum for one of the plurality of pixels, and calculating a plurality of estimated concentrations of each substance in the mixture as a function of the spectrum for each substance and the spectrum for the pixel, and calculating a deviation value for each of the plurality of estimated concentrations as a function of the spectrum of each of the number of substances in the mixture, and selecting the estimated concentration with the lowest deviation factor as a most likely concentration of each substance in the mixture (550).

Abstract: Inclinometer and directional field sensor readings can have gain, offset, and non-orthogonality errors, as well as reference alignment rotation errors. When a series of readings are taken by a three axis sensor with a variety of different orientations, the resulting dataset looks like a perfect hypothetical sphere in the absence of any errors; with errors as mentioned above the dataset looks like an offset, rotated, ellipsoidal quadratic surface. This invention provides a simple method of removing the above errors from a tilt reference device. A disclosed algorithm is divided into two distinct components: the ellipsoidal quadratic surface component, which covers gain, offset, and axis misalignment; and the rotation component, which covers rotation relative to a set of reference axes. The solution presented here addresses both components combined, or separated and for inclinometers, magnetometers and rate sensors.

Abstract: A system and method of controlling a sensor to sense one target from a plurality of targets includes predicting states of the targets. A set of probability distributions is generated. Each probability distribution in the set represents a setting or settings of at least one control parameter of the sensor. An expected information gain value for each control parameter in the set is calculated. The information gain value represents an expected quality of a measurement of one of the targets taken by the sensor if controlled according to the control parameter, based on the predicted state of the target. Updating the set of probability distributions takes place to identify the sensor control parameters that maximise the expected information gain value. The sensor is then controlled in accordance with the maximising control parameters.

Abstract: A computer system that processes mixtures of signals, such as speech and noise sources derived from multiple simultaneous microphone recordings, in order to separate them into their underlying sources. A source separation routine optimizes a filter structure by minimizing cross powers of multiple output channels while enforcing geometric constraints on the filter response. The geometric constraints enforce desired responses for given locations of the underlying sources, based on the assumption that the sources are localized in space.

Abstract: Methods and apparatus for analysis and design of radiation and scattering objects are disclosed. In one embodiment, unknown sources are spatially grouped to produce a system interaction matrix with block factors of low rank within a given error tolerance and the unknown sources are determined from compressed forms of the factors.

Abstract: A direction-of-arrival estimation apparatus has a signal vector generation unit operable to generate a signal vector v composed of N baseband signals v1 to vN from arriving signals received from a target by N sensors. The direction-of-arrival estimation apparatus includes a Hankel matrix generation unit operable to preferentially set an order of a column of a matrix at a natural number M where 1?M and M?(N?1)/2 and generate an (N?M)×M matrix Rf1, Rf2, Rb1, or Rb2 from elements v1 to vN-1 of the signal vector. The direction-of-arrival estimation apparatus also includes an estimation unit operable to generate a matrix R using the matrices Rf1, Rf2, Rb1, or Rb2, divide the matrix R into two submatrices R1 and R2 by R=[R1|R2]T, and estimate a direction of arrival of the arriving signal based on the submatrices R1 and R2.

Abstract: A measurement error correcting method and electronic component characteristic measuring device capable of accurately coping with an electronic component which includes nonsignal line ports and whose electrical characteristics are changed by a jig. The method includes the steps of measuring an electrical characteristic, with correcting-data-acquisition samples mounted on a test jig enabling measuring nonsignal line ports, and the samples mounted on a reference jig; measuring a through device in which a signal line port and a nonsignal line port are electrically connected to each other; determining a numerical expression for calculating, from results of measurement on the test jig, an estimated electrical characteristic value obtained on the reference jig; measuring an arbitrary electronic component, on the test jig; and calculating the estimated electrical characteristic value obtained on the reference jig.

Abstract: A method for estimating color measurements of color samples includes printing a color sample based on input data, measuring a color of the printed color sample with an in-line spectral sensor at a first temperature, and estimating a color of the printed color sample which would be output by a reference spectral sensor at a second temperature. The estimation is based on a thermochromatic model which represents relationships between measured colors of printed color samples on the in-line spectral sensor at the first temperature and the reference spectral sensor at the second temperature. The reference spectral sensor is a different type of sensor from the in-line spectral sensor, so the color response of the two spectral sensors is different, even when the measurement conditions are identical. Consequently, a set of printed spot color samples generate different measured colors at the second temperature on the in-line spectral sensor from the reference spectral sensor.

Abstract: A diagnostics system comprising a topological map of a target system that has nodes (38, 40, 42, 44, 46, 48) that correspond to components (29, 30, 32, 34, 36) of the target system and links that correspond to connections between the components. Associated with the topological map is a knowledge store (50) that has a structure that reflects or corresponds to that of the topological map. Included in this store (50) is a plurality of sections or libraries each of which is provided for storing design specific data associated with one of the nodes (38, 40, 42, 44, 46, 48) of the topological map. Data received from one or more sensors on the target system is included in the topological map, and used together with the design specific information in the knowledge store to diagnose faults.

Abstract: A compressive sensor array (CSA) system and method uses compressive sampling techniques to acquire sensor data from an array of sensors without independently sampling each of the sensor signals. In general, the CSA system and method uses the compressive sampling techniques to combine the analog sensor signals from the array of sensors into a composite sensor signal and to sample the composite sensor signal at a sub-Nyquist sampling rate. At least one embodiment of the CSA system and method allows a single analog-to-digital converter (ADC) and single RF demodulation chain to be used for an arbitrary number of sensors, thereby providing scalability and eliminating redundant data acquisition hardware. By reducing the number of samples, the CSA system and method also facilitates the processing, storage and transmission of the sensor data.

Abstract: The invention relates to a method for breaking down a set of signals consisting of an instantaneous linear mixture of independent components. The method comprises a step (200) consisting in estimating a mixture matrix A by using the product of one or more trigonometric rotation matrices by one or more hyperbolic rotation matrices.

Abstract: The invention relates to a control system for active vibration isolation of a supported payload with a control device that comprises a processing unit (41) for processing position data and orientation data of all available sensors to supply a sensor control matrix, as well as for subsequent calculation of axis input signals in orthogonal degrees of freedom from the sensor signals and the sensor control matrix, a downstream control-path cascade block (42) for processing axis input signals into axis output signals in orthogonal degrees of freedom, and a downstream processing unit (43) for processing position data and orientation data of all available actuators for vibration suppression into an actuator control matrix, as well as for subsequent calculation of actuator control signals from the axis output signals and the actuator control matrix.

Abstract: Methods and apparatus for signal processing are disclosed. A discrete time domain input signal xm(t) may be produced from an array of microphones M0 . . . MM. A listening direction may be determined for the microphone array. The listening direction is used in a semi-blind source separation to select the finite impulse response filter coefficients b0, b1 . . . , bN to separate out different sound sources from input signal xm(t). One or more fractional delays may optionally be applied to selected input signals xm(t) other than an input signal x0(t) from a reference microphone M0. Each fractional delay may be selected to optimize a signal to noise ratio of a discrete time domain output signal y(t) from the microphone array. The fractional delays may be selected to such that a signal from the reference microphone M0 is first in time relative to signals from the other microphone(s) of the array.

Abstract: A method is provide for providing sensors for a machine. The method may include obtaining data records including data from a plurality of sensors for the machine and determining a virtual sensor corresponding to one of the plurality of sensors. The method may also include establishing a virtual sensor process model of the virtual sensor indicative of interrelationships between at least one sensing parameters and a plurality of measured parameters based on the data records and obtaining a set of values corresponding to the plurality of measured parameters. Further, the method may include calculating the values of the at least one sensing parameters substantially simultaneously based upon the set of values corresponding to the plurality of measured parameters and the virtual sensor process model and providing the values of the at least one sensing parameters to a control system.

Abstract: Provides a diagnostic apparatus for diagnosing a measured object based on time-series data of a plurality of parameters measured from the measured object. An example of an apparatus includes a change-point score calculating portion for calculating a time-series change-point score with which each of the plurality of parameters changes according to passage of time based on the time-series data on the parameter, a change-point correlation calculating portion for calculating a change-point correlation indicating strength by which each of the plurality of parameters is associated with each of other parameters based on the change-point scores of the parameter and the other parameter, and a parameter outputting portion for outputting a set of parameters of which calculated degrees of associations are higher than a predetermined reference change-point correlation as a set of mutually strongly associated parameters.

Abstract: A frequency domain transforming section transforms mixed signals observed by multiple sensors into mixed signals in the frequency domain, a complex vector generating section generates a complex vector by using the frequency-domain mixed signals, a normalizing section generates a normalized vector excluding frequency dependence of the complex vector, and a clustering section clusters the normalized vectors to generate clusters. Then, a separated signal generating section generates separated signals in the frequency domain by using information about the clusters and a time domain transforming section transforms the separated signals in the frequency domain into separated signals in the time domain.

Abstract: Chromatograms and mass spectra produced by an LC/MS system are analyzed by creating a two-dimensional data matrix of the spectral and chromatographic data. The two-dimensional matrix can be created by placing the spectra generated by the mass spectrometer portion of the LC/MS system in successive columns of the data matrix. In this way, the rows of the data matrix correspond to chromatographic data and the columns of the data matrix correspond to the spectra. A two-dimensional filter is specified and applied to the data matrix to enhance the ability of the system to detect peaks associated with ions. The two-dimensional filter is specified according to desired criteria. Rank-1 and rank-2 filters can be specified to improve computational efficiency. One method of applying the two-dimensional filter is through convolution of the data matrix with the two-dimensional filter to produce an output data matrix. Peaks corresponding to detected ions are identified in the output data matrix.

Abstract: The device determines the weighting coefficients to be applied to N digital source signals to form a composite signal. The first- to third-order moments of the composite signal must respectively present mean value, variance and skewness characteristics predefined by a user. The device introduces an additional variable, in the form of a weighting matrix W. The vector w being the vector of the weighting coefficients and wT the transpose of the vector w, the difference W?wwT is a positive semidefinite matrix. Moreover, the device performs linearization, around a vector wref of reference weighting coefficients, of the skewness constraint on the third-order moments using a matrix A = [ W w w T 1 ] as further intermediate variable.

Abstract: A projection is associated with a first signal and a second signal. The second signal includes a first portion associated with the first signal and a second portion not associated with the first signal. The projection at least substantially separates the first portion of the second signal from the second portion of the second signal. One or more parameters of a model are identified using at least a portion of the projection. The model associates the first signal and the first portion of the second signal.

Abstract: A method detects a change in a stream of samples acquired by a sensor. A stream of samples acquired by a sensor over time is stored sequentially in a buffer in which an oldest sample is discarded and a newest sample is stored when the buffer is full such that the buffer forms a window of samples sliding forward in time. For each new sample, the buffer is partitioned into all possible pairs of contiguous sub-windows of samples including a first sub-window and a second sub-window such that the newest sample is stored in the second sub-window of the pair. A difference is determined between the first and second sub-window of each pair of the contiguous sub-windows of samples, and a maximum difference is assigned as a merit score. A change in the stream of samples is signaled if the merit score is greater than a predetermine threshold. The change can be abrupt or gradual.

Abstract: To generate a reference database for a particular sensor in a multiple LED spectrophotometric system with a reduced number of test measurements taken from training samples, a first set of reflectance reference measurements are generated from a test target on to a reference sensor from a plurality of different LED emissions. A first spectral reconstruction reference matrix is computed by performing an operational characterization of the reference sensor from the first set of reflectance reference measurements. A second set of reflectance reference measurements from the test target is generated from a second subject sensor whose operation is to be personalized by the objective reference database. The second set of reflectance reference measurements are less in number than the first set. A second reconstruction matrix is computed by performing an operational characterization of the subject sensor from the second set of measurements.

Abstract: Systems and methods for the design or implementation of statistical filters for use in the spectral shaping of transmissions are disclosed. A desired power spectrum may be mapped to find pole locations that approximate the desired spectrum. These pole locations may then be mapped to the edge or inside of an equilateral polygon lying inside a unit circle, the equilateral polygon having the same number of sides as the order of the statistical filter desired and one vertex mapped to unity, to yield a set of eigenvalues. These eigenvalues may be the eigenvalues of a stochastic matrix the elements of which may be the Markov transition probabilities for use in a statistical filter designed to achieve the desired power spectrum. Use of a statistical filter employing these Markov transition values may be utilized to shape UWB or other signals to achieve the desired power spectrum.

Abstract: A method and apparatus is operative for multiple target detection in a radar system which employs a radar waveform of two or more frequency diverse subpulses. The apparatus adds coherent processing of the subpulse echo signals to determine the presence of multiple scattering centers within the radar resolution cell. The subpulses are coherently combined and one can then estimate the number of scattering centers by forming a sample covariance matrix between the subpulse frequency channels and then performing an Eigenvalue decomposition. The resulting Eigenvalues represent the signal strengths of the scattering centers when the associated Eigenvectors correspond to the optimal subpulse weights associated with that signal. A single strong Eigenvalue indicates a single target while two or more strong Eigenvalues or those Eigenvalues larger than the noise related Eigenvalues or a threshold, indicates the presence of multiple targets.

Abstract: Systems and methods are provided for monitoring, diagnosis and condition-based maintenance of mechanical systems. The disclosed systems and methods employ intelligent model-based diagnostic methodologies to effectuate such monitoring, diagnosis and maintenance. According to exemplary embodiments of the present disclosure, the intelligent model-based diagnostic methodologies combine or integrate quantitative (analytical) models and graph-based dependency models to enhance diagnostic performance. The disclosed systems and methods may be employed a wide variety of applications, including automotive, aircraft, power systems, manufacturing systems, chemical processes and systems, transportation systems, and industrial machines/equipment.

Abstract: A method of analyzing a dataset of spectra is provided in which each spectrum has a count value for each of a number of parameter values within a parameter range. The method is for identifying one or more parameter values that exhibit a significant variation within the dataset. A dataset of spectra is obtained and a statistical analysis is applied to the count values for each of the parameter values. The result of the analysis for each parameter value is a function of the variation in the count values. A spectrum that is representative of at least part of the dataset of spectra is then displayed together with the results of the statistical analysis. A corresponding computer program and system for performing the method are also disclosed.

Abstract: A system and method to evaluate characteristics of transient events in an electrical power system to determine the location of a transient source type, the source type of a transient event, and suggested mitigation measures that might reduce or eliminate the effects of the transient. The electrical power system has a plurality of monitoring devices that each may detect the occurrence of a transient event incident upon the power system. A controller is coupled to the monitoring devices. The monitoring devices measure signal parameter values associated with the transient event, and the location of the transient event is automatically determined by evaluating transient characteristics from each of the recording monitoring devices. Other measurements of signal parameters may be made to determine transient characteristics.

Abstract: A method for monitoring of and fault detection in an industrial process, comprising at least a first sub-process and at least one second sub-process arranged in a process chain, comprising, for the at least one second sub-process the steps of collecting data and calculating a multivariate sub-model based on the collected data, said method being characterized by the steps of receiving in the first sub-process from the at least second sub-process information related to the multivariate sub-model calculated for the at least second sub-process, collecting data related to the first sub-process, and calculating a multivariate sub-model for the first sub-process based on collected data and received information.

Abstract: A method for preparing peptide spectra for identification, the method including constructing a symmetric distance matrix from a plurality of peptide spectra, where a cluster of at least one of the spectra is represented in a row of the matrix, and where the cluster is also represented in a column of the matrix, finding the minimum of each of the clusters in the matrix, constructing a vector from the minima where each element in the vector corresponds to one of the clusters, finding the global minimum of the matrix as being the minimum of the vector, merging two of the clusters identified by the global minimum into a merged cluster, and providing the merged cluster for identification of at least one peptide associated with the merged cluster.

Abstract: A method of generating sample data from a computerized model of a mass using acoustic simulations is disclosed. Initially, a computerized model of the mass is created based upon information that is known about the mass. The computerized model is divided into a plurality of layers, each layer representing physical features of the mass. Each layer is thereafter characterized by a propagation wavenumber. Acoustic wave equations for the layered model are then solved using a multi-level generalized minimal residual (GMRES) algorithm. The solved wave equations are employed to simulate acoustic data which is saved in an electronic memory for future use.

Abstract: A method and a device for signal separation. First, values of signals observed by M sensors are transformed into frequency domain values, and these frequency domain values are used to calculate relative values of the observed values between the sensors at each frequency. These relative values are clustered into N clusters, and the representative value of each cluster is calculated. Then, using these representative values, a mask is produced to extract the values of the signals emitted by V (1?V?M) signal sources from the frequency-domain signal values, and this mask is applied to the frequency-domain signal values. After that, if V=1 then the limited signal is output directly as a separated signal, while if V?2 then the separated values are obtained by separating this limited signal with separation techniques such as ICA.

Abstract: Control of an active vibration isolation system with a digital controller, which includes an FPGA system (5) as the control unit. The FPGA system (5) is made up of freely programmable gate arrays with a sensor control matrix (51), which calculates axis signals in required degrees of freedom, with a control cascade block (53) for the axis signals containing several biquad filters (531, 532, 533, 534, 535), and with an output signal calculation block (55) for calculating digital actuator actuation signals. A digital signal processor (9) is connected in parallel with the FPGA system (5) in order to calculate controls with low phase loss requirements.

Abstract: Disclosed herein are methods of analysis for unmixing non-linear, cross-reactive sensors and related system. Use of the disclosed methods, related systems and computer program product permits better analysis of the magnitudes of various stimulants including but not limited to chemical concentrations. One method may add one or more additional signal vectors to the sensor response before linearizing each channel. A second method may add one or more exponential terms to the response curve when using curve parameterization to unmix the sensor response. A third method may use non-linear iterative solutions that estimates an optical depth, linearizes the optical depth, solves for a correction to the estimated optical depth, and updates the optical depth. Also, the disclosed methods and related systems include combinations of the methods described herein.

Abstract: A largest eigenvalue is determined among eigenvalues corresponding to a correlation matrix indicating correlations between a plurality of channels receiving incoming radar waves from an object that reflects a radar wave as a reference eigenvalue ?1. A ratio R?i (=10 log 10(?i/?1)) is calculated of each eigenvalue ?2 to ?N to the reference eigenvalue ?1. Eigenvalues among the reference eigenvalue ?1 and the eigenvalues ?2 to ?N of which the eigenvalue ratio R?i is greater than a noise threshold TH are identified as eigenvalues in signal space. Eigenvalues of which the eigenvalue ratio R?i is equal to the noise threshold TH or less are identified as eigenvalues in noise space. The number of eigenvalues identified as the eigenvalues in signal space is counted as the number of arrival signals.

Abstract: Specific wavelengths to use in optical metrology of an integrated circuit can be selected using one or more selection criteria and termination criteria. Wavelengths are selected using the selection criteria, and the selection of wavelengths is iterated until the termination criteria are met.

Abstract: Noise discrimination in signals from a plurality of sensors is conducted by enhancing the phase difference in the signals such that off-axis pick-up is suppressed while on-axis pick-up is enhanced. Alternatively, attenuation/expansion are applied to the signals in a phase difference dependent manner, consistent with suppression of off-axis pick-up and on-axis enhancement. Nulls between sensitivity lobes are widened, effectively narrowing the sensitivity lobes and improving directionality and noise discrimination.

Abstract: A performance manager and method for managing the performance of a computer system based on a system model that includes measured entities representing the operational characteristics of the system components and relationships among the measured entities. The performance manager includes data producers for interacting with the interface agents of the components, an engine for exchanging information with the data producers and the system model, and an interaction model for determining relevant measured entities in the system model. The system model and interaction model are maintained in a repository where data might be accessed via an access interface. Incoming performance data is analyzed by an analyzer in the background to detect trends and relationships among the entities. An operator might review the relevant entities and apply controls to selected entities to manage the overall system performance as well as to resolve problems affecting the performance of the components in the system.

Abstract: Two sensors scan a measuring scale, which can be displaced in relation to the sensors and comprises a plurality of equidistant measuring gradation, and deliver corresponding measuring signals. The measuring signals are periodic during a uniform relative displacement of the measuring scale, essentially sinusoidal and essentially phase-shifted by 90° in relation to one another. They have an essentially identical amplitude and a base frequency that corresponds to the relative displacement of the measuring scale. During a delivery period of measuring signals, the measuring scale carries out a relative displacement through one measuring gradation. Corrected signals are determined from the measuring signals using correction values. A signal of the position of the measuring scale in relation to the sensors is determined in turn using said correction signals.