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5574 results about "Correlation coefficient" patented technology

A correlation coefficient is a numerical measure of some type of correlation, meaning a statistical relationship between two variables. The variables may be two columns of a given data set of observations, often called a sample, or two components of a multivariate random variable with a known distribution.

System for bandwidth extension of Narrow-band speech

A system and method are disclosed for extending the bandwidth of a narrowband signal such as a speech signal. The method applies a parametric approach to bandwidth extension but does not require training. The parametric representation relates to a discrete acoustic tube model (DATM). The method comprises computing narrowband linear predictive coefficients (LPCs) from a received narrowband speech signal, computing narrowband partial correlation coefficients (parcors) using recursion, computing Mnb area coefficients from the partial correlation coefficient, and extracting Mwb area coefficients using interpolation. Wideband parcors are computed from the Mwb area coefficients and wideband LPCs are computed from the wideband parcors. The method further comprises synthesizing a wideband signal using the wideband LPCs and a wideband excitation signal, highpass filtering the synthesized wideband signal to produce a highband signal, and combining the highband signal with the original narrowband signal to generate a wideband signal. In a preferred variation of the invention, the Mnb area coefficients are converted to log-area coefficients for the purpose of extracting, through shifted-interpolation, Mwb log-area coefficients. The Mwb log-area coefficients are then converted to Mwb area coefficients before generating the wideband parcors.
Owner:CERENCE OPERATING CO

Combined wind power prediction method suitable for distributed wind power plant

The invention provides a combined wind power prediction method suitable for a distributed wind power plant. The method comprises the following steps: step 1, acquiring data and pre-processing; step 2, utilizing a training sample set and a prediction sample set which are normalized to build a wind speed prediction model based on a radial basis function neural network and predict the wind speed and variation trend of distribution fans at the next moment; step 3, building a distributed wind power plant area CFD (computational fluid dynamics) model and externally deducing the prediction wind speed of each fan in the plant area according to factors such as the terrain, coarseness and wake current influence of a distributed wind field; step 4, acquiring the power data of an SCADA (supervisory control and data acquisition) system fan of the distributed wind field; and step 5, adopting correlation coefficients. The invention firstly provides a double-layer combined neural network to respectively predict the wind speed and power. Models are respectively built through adopting appropriate efficient neural network types, and improved particle swarm optimization with ideas of 'improvement', 'variation' and 'elimination' is additionally added to optimize the neural network, so that the speed and precision of modeling can be effectively improved, and the decoupling between wind speed and power is realized.
Owner:LIAONING ELECTRIC POWER COMPANY LIMITED POWER SCI RES INSTION +2

Method of bandwidth extension for narrow-band speech

A system and method are disclosed for extending the bandwidth of a narrowband signal such as a speech signal. The method applies a parametric approach to bandwidth extension but does not require training. The parametric representation relates to a discrete acoustic tube model (DATM). The method comprises computing narrowband linear predictive coefficients (LPCs) from a received narrowband speech signal, computing narrowband partial correlation coefficients (parcors) using recursion, computing Mnb area coefficients from the partial correlation coefficient, and extracting Mwb area coefficients using interpolation. Wideband parcors are computed from the Mwb area coefficients and wideband LPCs are computed from the wideband parcors. The method further comprises synthesizing a wideband signal using the wideband LPCs and a wideband excitation signal, highpass filtering the synthesized wideband signal to produce a highband signal, and combining the highband signal with the original narrowband signal to generate a wideband signal. In a preferred variation of the invention, the Mnb area coefficients are converted to log-area coefficients for the purpose of extracting, through shifted-interpolation, Mwb log-area coefficients. The Mwb log-area coefficients are then converted to Mwb area coefficients before generating the wideband parcors.
Owner:NUANCE COMM INC

Multiple-input multiple-output spatial multiplexing system with dynamic antenna beam combination selection capability

The present invention generally relates to the field of wireless communication systems. It particularly refers to a spatial diversity transmitter (110) and a spatial diversity receiver (120) in a wireless multiple-input multiple-output (MIMO) spatial multiplexing system as well as a corresponding method for wirelessly transmitting and receiving modulated RF signals via multiple wireless signal propagation paths (Pl) of a multipath fading channel in a way that correlation between the MEMO channel components are reduced and/or the signal to interference plus noise ratio (SINR) is increased which hence result in an improved bit error rate (BER) or packet error rate (PER) performance of said wireless MIMO spatial multiplexing system. On the receiver side, for example, this is achieved by controlling at least one antenna switching and/or combining means (121a′+b′) to select a specific combination of different fixed beam antennas (121a+b) from each receiver-resident antenna array. According to the invention, said selection is based on estimated values of the channel impulse responses (hll, t)) for said signal propagation paths (Pl). An antenna beam selection control means (129) is configured for selecting a specific antenna beam combination so as to maximize the average signal-to-interference-plus-noise ratios ( γl) of RF signals (rll, t, φl)) received via said multiple wireless signal propagation paths (Pl) and/or to minimize the correlation coefficients (ρr<sub2>l1</sub2>r<sub2>l2</sub2>(t)) indicating the correlations of different pairs of these RF signals (rl1l1, t, φl1) and rl2l2, t, φl2)).
Thereby, each fixed beam antenna (121a+b) of the receiver-resident antenna arrays has a distinct radiation pattern with a different beam center and/or beam width in the azimuth and/or elevation plane, wherein a superposition of all these radiation patterns may cover all possible azimuthal (φ) and/or elevational angles of arrival (θ) of an RF signal (s(t)).
For compensating detected multipath fades in the channel amplitude response (|Hl(f, t)|) of at least one signal propagation path (Pl) between the spatial diversity transmitter (110) and the spatial diversity receiver (120), a receiver-resident channel estimation and/or equalization circuitry (124, 128) is applied.
Owner:SONY DEUT GMBH

Ultrasonic flux detection system and detection method

The invention belongs to the detection field, and relates to an ultrasonic wave flow rate detecting system and a detecting method, in particular to a high-precision fluid flow rate ultrasonic wave detecting system and a detecting method. The ultrasonic wave flow rate detecting system includes a system control part, a circuit part and an auxiliary device. The ultrasonic wave flow rate detecting method is characterized in that an improved time difference method is adopted for calculating the speed of a fluid; the delay window reception technique is adopted, and the influence of noise on the detection precision during detection is reduced through pulse width detection; and as the resolution of measuring time for the system is further improved through the adoption of the interpolation correlation method and the correlation coefficient judgment method, and reaches 1.25ns, the accuracy and the precision of the ultrasonic flow-meter are remarkably improved. The detecting system provided by the invention has the characteristics of small size, low power consumption, stable and reliable measurement and the like; the precision reaches 0.5; the sensitivity attains 0.3mm/s; and the system is suitable for measuring the flow rates and the flow velocities of various liquids in plastic or metal pipes with diameters being 25mm-8m.
Owner:SHENZHEN POLYTECHNIC

Optimal power flow optimization method of distributed power supplies

The invention relates to an optimal power flow optimization method of distributed power supplies. The optimal power flow optimization method of the distributed power supplies includes the following steps: A, variable in a distribution network is initialized; B, load flow calculation is carried out on the distribution network; C, lines are judged to be overloaded or not, and active output force and reactive output force of an engine and the distributed power supplies are judged to overstep the boundary or not; D, if constraint equations are all met, a step E is continued, otherwise a step F is continued; E, an objective function is judged to be the minimum or not, if the objective function is the minimum, a step J is continued, otherwise a step F is continued; F, net loss correlation coefficients are corrected; G, a Jacobean matrix and a Hessian matrix are calculated; H, a problem of sequential quadratic programming is formed and the search direction and a step size are solved; I, output force at the position of a balancing node bus and output force of each distributed power supply are corrected, and the step B is jumped to; and J, an optimal power flow result is output. The optimal power flow optimization method of the distributed power supplies provides basis of access capacity calculation for determining the distributed power supplies to be connected in a power distribution network, is simple in calculation and low in complexity, and can rapidly calculate the output force of the distributed power supplies.
Owner:CHINA ELECTRIC POWER RES INST +1

Image characteristic matching method

The invention relates to an image characteristic matching method. The image characteristic matching method includes the steps of pre-processing an obtained CCD (charge coupled device) image; extracting characteristic points of the pre-processed CCD image by a SURF operator and conducting matching image by the quasi epipolar line limit condition and minimum Euclidean distance condition to obtain the identical point information; establishing affine deformation relation between the CCD images according to the obtained identical point information; extracting the characteristic points of a reference image by Harris corner extracting operator, projecting the characteristics points to a searching image by the affine transformation to obtain points to be matched; in neighbourhood around the points to be matched, counting the correlation coefficient between the characteristic points and the points in the neighbourhood and taking extreme points as the identical points; and using the comprehensive results of twice matching as the final identical point information. According to the method of the invention, can match surface images of deep-space stars obtained in a deep-space environment is utilized for imaging matching to obtain high-precision identical point information of CCD images, so that the characteristic matching is realized.
Owner:THE PLA INFORMATION ENG UNIV

Method for simultaneously determining one hundred pesticide residuals in traditional Chinese medicine through ultrahigh performance liquid chromatography-tandem quadrupole mass spectrum

The invention provides a method for simultaneously determining one hundred pesticide residuals in a traditional Chinese medicine through ultrahigh performance liquid chromatography-tandem quadrupole mass spectrum. The method comprises the following steps: immersing traditional Chinese medicine powder with ultrapure water, extracting with acetonitrile containing 0.1% acetic acid through a homogenate method, carrying out solid phase dispersing purification with N-propylethylenediamine and graphitized carbon, detecting in a timesharing multi-reaction monitoring mode through the ultrahigh performance liquid chromatography-tandem quadrupole mass spectrum, and quantifying with an external standard curve method. 88% of pesticides have good linear relations in a range of 5-500ng/mL, correlation coefficients are above 0.99, and the correlation coefficients of above 98% of the pesticides are above 0.97; the average recovery rate of the pesticides with the low concentration of 10mug/kg, the middle concentration of 50mug/kg and the high concentration of 100mug/kg is 70-130%, and the relative standard deviation is less than 0.15; and the detection limit is equal to or less than 0.01mg/kg, so routine detection requirements can be completely satisfied. The method has the advantages of strong versatility, good selectivity, high sensitivity, and rapidness and simplicity.
Owner:CHANGCHUN INST OF APPLIED CHEMISTRY - CHINESE ACAD OF SCI
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