451 results about "Linear approximation" patented technology

A method of performing bilateral filtering and using the method for displaying high-dynamic-range images is presented. The method reduces the contrast of the image while preserving detail of the image. The presently disclosed method incorporates a two-scale decomposition of the image into a base layer encoding large-scale variations, and a detail layer. The base layer has its contrast reduced, thereby preserving detail. The base layer is obtained using an edge-preserving bilateral filter. The bilateral filter is a non-linear filter, where the weight of each pixel is computed using a Gaussian in the spatial domain multiplied by an influence function in the intensity domain that decreases the weight of pixels with large intensity differences. The bilateral filtering is accelerated by using a piecewise-linear approximation in the intensity domain and appropriate subsampling.

In an OFDM transmission scheme, in order to compensate any frequency response variations time wise resulted from any distortion in a transmission path, out-of-synchronization with passage of time, frequency drift, and phase shift, and to improve a demodulation characteristic, a PS detector in a receiver receiving an OFDM signal detects a pilot symbol. A PS1 TPFR calculator calculates a frequency response of the transmission path for a first pilot symbol, while a PS2 TPFR calculators calculates a frequency response of the transmission path for a second pilot symbol for a second pilot symbol. Thereafter, a compensation vector calculator calculates compensation vectors from the frequency responses of the transmission path for both of the first and second pilot symbols by linear approximation. A frequency response compensatory compensates the frequency response variation of subcarriers in a data symbol based on the calculated compensation vectors.

An efficient computation of low-dimensional linear subspaces that optimally contain the set of images that are generated by varying the illumination impinging on the surface of a three-dimensional object for many different relative positions of that object and the viewing camera. The matrix elements of the spatial covariance matrix for an object are calculated for an arbitrary pre-determined distribution of illumination conditions. The maximum complexity is reduced for the model by approximating any pair of normal-vector and albedo from the set of all such pairs of albedo and normals with the centers of the clusters that are the result of the vector quantization of this set. For an object, a viewpoint-independent covariance matrix whose complexity is large, but practical, is constructed and diagonalized off-line. A viewpoint-dependent covariance matrix is computed from the viewpoint-independent diagonalization results and is diagonalized online in real time.

This invention relates to methods and devices for time synchronization. The invention has particular application in the alignment of slave clocks to a master clock and in dealing with packet delay variation and dynamic asymmetries in the network links between them. In embodiments of the invention, the slave clock uses the peer link delay and residence times measured by peer-to-peer transparent clocks to compensate for clock synchronization errors that arise due to variability in message transfer delays. Embodiments provide a simple linear approximation technique and a Kalman filter-based technique for estimating offset and skew of the slave clock.

An efficient method to compute critical area for shorts and breaks in rectilinear layouts in Very Large Scale Integrated (VLSI) circuits. The method is incremental and works in the L INFINITY geometry and has three major steps: Compute critical area for rectilinear layouts for both extra material and missing material defects (i.e., shorts and opens) by modeling defects as squares (which corresponds to the L INFINITY metric) instead of circles (Euclidean geometry). Treat the critical region for shorts and opens between any two edges or corners of the layout as a rectangle that grows uniformly as the defect radius increases. This is valid for rectilinear layouts and square defects (L INFINITY metric) . Use an incremental critical area algorithm for shorts and opens, which are computed for rectilinear layouts assuming square defects. Non-rectilinear layouts are approximated, first, by a rectilinear layout using a shape processing tool. The critical area for the rectilinear approximation is computed using the preferred incremental method.

This invention relates to methods and devices for clock synchronization. The invention has particular application in the alignment of slave clocks to a master clock and in dealing with transmission delay asymmetries where the forward and reverse communication paths between the master and slave clocks have asymmetric transmission rates. Such methods and devices have particular application in small cell backhaul solutions for 4G / LTE deployments. In embodiments of the invention, the slave clock uses link rate information to estimate the transmission delay asymmetry and thus estimate the offset and skew of the slave clock. Embodiments provide a simple linear approximation technique and a Kalman filter-based technique for estimating offset and skew of the slave clock.

A constrained non-linear approximator for empirical process control is disclosed. The approximator constrains the behavior of the derivative of a subject empirical model without adversely affecting the ability of the model to represent generic non-linear relationships. There are three stages to developing the constrained non-linear approximator. The first stage is the specification of the general shape of the gain trajectory or base non-linear function which is specified graphically, algebraically or generically and is used as the basis for transfer functions used in the second stage. The second stage of the invention is the interconnection of the transfer functions to allow non-linear approximation. The final stage of the invention is the constrained optimization of the model coefficients such that the general shape of the input / output mappings (and their corresponding derivatives) are conserved.

A system and method is described for rendering a warped brush stroke using a bitmap brush image, the brush stroke being along a arbitrarily curved guideline. The described system and method generate a piecewise linear approximation to the guideline followed by generating polygons with the aid of the linear segments such that the generated polygons are convex and contiguous linear segments result in contiguous polygons. A mapping is identified between segments of the bitmap brush and the polygons such that the corners or the boundaries of the segments of a segment map to the corners or boundaries of a corresponding polygon. The segment of the bitmap brush is mapped into the corresponding polygon using transformations that do not require visiting a pixel in the rendered warped brush stroke more than once. Examples of such transformations include bilinear transformations and texture mapping in combination with tiling.

A three-phase DC motor output stage including a predriver that supplies drive voltages to power MOSFETs supplies output voltages to three-phase coils, monitors whether each of gate-to-source voltages of the power MOSFETs is greater than or equal to a predetermined voltage and thereby detects a current zero cross, and employs the output of such current zero cross detection in PLL control for controlling energization switching timing and thereby forms drive voltages of 180-degree energization. Lower hooks with a voltage minimum phase as GND and upper hooks with a voltage maximum phase as a source are set as patterns alternately repeated for every electrical angle of 60 degrees. The patterns are expressed in linear approximation to generate sine wave-like drive voltages, thereby causing sine wave-like currents to flow into the three-phase coils.

The invention provides a tag communication device, a tag moving direction detecting system and a tag moving direction detecting method able to detect the moving direction of a moving body attaching a RFID tag thereto by simple processing, and able to easily detect the moving direction even when its moving speed is increased. A scan antenna scans a beam of a transmitted radio wave toward a belt conveyer for conveying baggage with a RFID tag. ID is read from the RFID tag, and reading NO. and a scan angle are related and recorded to a measuring data table, and plot data are generated. These plot data are plotted in an XY coordinate system, and a plot graph is generated. Further, a linear approximate straight line is calculated from this plot graph, and a moving direction of the baggage is detected from an inclination value of the linear approximate straight line.

Based on a plurality of valid data sets from a data set selection portion, an internal-resistance-during-charging calculation portion calculates the value Rc of internal resistance during charging from the slope of a voltage-current linear approximation during charging, and an internal-resistance-during-charging-and-discharging calculation portion calculates the value Rcd of internal resistance during charging and discharging from the slope of a voltage-current linear approximation during charging and discharging. A judgment portion compares the absolute value ΔR of the difference between Rcd and Rc that has been calculated by a difference computation portion with a first predetermined value ΔRT1, and when ΔR≦ΔRT1 is satisfied, the judgment portion outputs Rcd or Rc, whichever is smaller, as the value of internal resistance of a secondary battery.

The present invention involves a method and an apparatus capable of calculating, in real time, option-embedded coupon bearing bonds by option adjusted spread and linear approximation. The linear approximation uses a first order partial derivative to calculate a vector of sensitivities of bond price against yield curve by which an nth order linear approximation of the bond price can be approximated. The apparatus comprises a plurality of trader's workstations, one of which may serve as an option adjusted spread lattice engine for full lattice computation. The trader's workstations may be actuated by a triggering object, which receives yield curve, bond price, spread, volatility and other bond information updates from a database server. For each security, the Lattice Engine uses the lattice method to compute the price of the security and a vector of partial derivatives of the security price with respect to the yield curve. While other workstations, upon receiving any update of the yield curve, use the results of the Lattice Engine to perform first order approximation of the security prices. Since linear approximation is a simple calculation, the price update of a large number of securities can be carried out in real time. Because the Lattice Engine recalculates the first order partial derivatives when the yield curve has changed significantly, the linear approximations are very accurate in general.

The invention aims at providing an orthogonal frequency division multiplexing (OFDM) underwater acoustic communication parallel iterative inter-carrier interference (ICI) elimination method. The method includes the steps of building an OFDM underwater acoustic communication system, building an acoustic time varying multipath channel model, measuring Doppler factors in the system, estimating frequency response of a time varying channel, estimating an ICI component and a signal interference noise ratio (SINR), and carrying out parallel iterative minimum mean square error (MMSE) equilibrium to received signals. Through combination of a linear approximation method and the MMSE method, and through iteration to improve performance, the parallel iterative ICI elimination method is inducted into the OFDM underwater acoustic communication system, and the method can effectively resist the ICI generated under the underwater acoustic time varying channel, and the OFDM underwater acoustic communication system is steady in response to the change of channel time varying speed. Therefore, inverse operation of a high order matrix is avoided, complexity of the method is reduced, and arithmetic speed is improved.

The invention discloses a super-resolution face recognition method based on deep belief networks, and relates to the technical field of face recognition. From a cognitive perspective, it is believed that an intrinsic relation exists between mutually corresponding face images differing in resolutions. But previous studies show that the method for expressing the intrinsic relation by linear approximation is restricted by linear approximation. Therefore, it is believed that the intrinsic relation is nonlinear. In view of outstanding performances of an artificial neural network on the nonlinear classification problem, a neural network algorithm is adopted to capture the nonlinear relation of the mutually corresponding face images differing in resolutions under the condition of posture change. Both theoretical research and neurophysiological research show that a deep structure, such as a system constructed by multiple layers of nonlinear processing units, should be constructed to build an intelligent processing system. According to the face recognition method, deep belief networks are adopted to extract a common nonlinear structure shared by mutually corresponding face images differing in resolutions.

A method for performing pre-stack time migration of seismic data in a region where the subsurface seismic wave propagation velocity varies in both the vertical direction and a horizontal direction. The migration is performed in the wave number—frequency domain and involves using travel time maps to find a linear fitting of the migration phase shift for a given ray parameter and at a given vertical depth versus horizontal position. The slope and intercept parameters from the linear fit are used to adjust a known pre-stack time migration equation, with the accuracy of the linear approximation requiring mild horizontal velocity variation.

A system and method are provided for designing RF pulses for multi-channel and / or multi-dimensional spatially-selective applications using a linear approximation. Embodiments of the system and method may use a generalized linear-class large tip angle approximation to design RF pulses for multi-channel and parallel transmission. Further, some of these approximations allow for the design of arbitrarily large flip angles, irregularly-shaped flip angle profiles, or arbitrary initial magnetization values. Embodiments of the system and method may also provide for the design of k-space trajectories which aid in maintaining assumptions of the various linear class approximations.

A detection apparatus includes a sample holding section, an irradiation means, a detection means, a calculation means, and an evaluation means. The irradiation means irradiates a substance held in the sample holding section with a THz wave. The detection unit detects a THz wave passed through or reflected from the substance. The calculation unit determines a frequency dependence of a property of the substance with respect to the irradiated THz wave and then calculates a slope of a straight line or a slope of a straight line obtained by straight-line approximation of the frequency dependence of the property of the substance. The evaluation unit evaluates the state change of the substance by comparing a previously-obtained slope of a straight line of the frequency dependence of the property of the substance in a standard state and the slope of the straight line of the substance calculated.

Method and apparatus for finding an assignment of voltages to all power domains of an integrated circuit such that the power consumption of an integrated circuit design is minimized and timing requirements (signal propagation delay or slack) are met. This is done by modeling both internal and external signal paths in an integrated circuit which has a number of power domains. The relationship between slack and voltage for the external and internal signal propagation paths is modeled, typically as a linear approximation. The integrated circuit design is then abstracted to a simplified form in terms of power domain relations and a model is created and solved iteratively using, e.g., linear programming, of different voltage levels for each power domain and including the slack values and their relationship between the changes in voltage and slack, for both the internal and external paths.

High frequency components of audio signals are reconstructed from the aspects of envelope and fine detail. The envelopes of the high frequency components are found through linear extrapolation of signals with frequencies lower than a cutoff frequency point. One method of reconstructing high frequency components is based on the linear extrapolation on the logarithm scale magnitudes of the transform coefficients of the audio signal in a frequency domain. The linear extrapolation is a linear approximation based on minimizing least squares of the logarithm scale magnitudes of the transform coefficients of the low frequency components. Another method is based on the linear extrapolation on the logarithm scale magnitudes of the envelope elements of the filterbank signals of the audio signal over a time segment. The linear extrapolation is a linear approximation based on minimizing least squares of the logarithm scale magnitudes of the envelope elements of the low frequency filterbank signals.

A constrained non-linear approximator for empirical process control is disclosed. The approximator constrains the behavior of the derivative of a subject empirical model without adversely affecting the ability of the model to represent generic non-linear relationships. There are three stages to developing the constrained non-linear approximator. The first stage is the specification of the general shape of the gain trajectory or base non-linear function which is specified graphically, algebraically or generically and is used as the basis for transfer functions used in the second stage. The second stage of the invention is the interconnection of the transfer functions to allow non-linear approximation. The final stage of the invention is the constrained optimization of the model coefficients such that the general shape of the input / output mappings (and their corresponding derivatives) are conserved.

A three-phase DC motor output stage including a predriver that supplies drive voltages to power MOSFETs supplies output voltages to three-phase coils, monitors whether each of gate-to-source voltages of the power MOSFETs is greater than or equal to a predetermined voltage and thereby detects a current zero cross, and employs the output of such current zero cross detection in PLL control for controlling energization switching timing and thereby forms drive voltages of 180-degree energization. Lower hooks with a voltage minimum phase as GND and upper hooks with a voltage maximum phase as a source are set as patterns alternately repeated for every electrical angle of 60 degrees. The patterns are expressed in linear approximation to generate sine wave-like drive voltages, thereby causing sine wave-like currents to flow into the three-phase coils.

A constrained non-linear approximator for empirical process control is disclosed. The approximator constrains the behavior of the derivative of a subject empirical model without adversely affecting the ability of the model to represent generic non-linear relationships. There are three stages to developing the constrained non-linear approximator. The first stage is the specification of the general shape of the gain trajectory or base non-linear function which is specified graphically, algebraically or generically and is used as the basis for transfer functions used in the second stage. The second stage of the invention is the interconnection of the transfer functions to allow non-linear approximation. The final stage of the invention is the constrained optimization of the model coefficients such that the general shape of the input / output mappings (and their corresponding derivatives) are conserved.

A method for detecting intrusion into an in-vehicle network using an intrusion detection system (IDS) of a vehicle includes: receiving messages of the in-vehicle network in a preset cycle, calculating a current count value per message of the received messages, receiving operation state information of the vehicle when the cycle starts, determining a normal count value per message corresponding to the operation state information, calculating a linearly approximated relative distance function per message using the current count value and the normal count value, and determining whether an intrusion state occurs by comparing the calculated linearly approximated relative distance function per message to a preset threshold value.

A linear regression equation is comprised of the objective variables and the explanatory variables. The objective variables are comprised of the L1 carrier phases, the L2 carrier phases, the C / A code pseudorange, the P(Y) code pseudorange, the clock error data, the delay data of the ionosphere, and the delay data of the troposphere that related with every satellite respectively. The explanatory variables are comprised of at least the integer ambiguity and a receiver's position.The receiver's position has been linear-approximated by using the estimation results of the passed receiver's positions. Applying a least square method to the regression equation, the integer ambiguity and the receiver's position is estimated.