Patents
Literature
Patsnap Copilot is an intelligent assistant for R&D personnel, combined with Patent DNA, to facilitate innovative research.
Patsnap Copilot

303 results about "System matrix" patented technology

The matrix is built up by multiplying the refraction matrices and translation matrices. The positions of the principal planes, the front and back surface powers, and the equivalent focal length of Gullstrand's equation can be calculated from the system matrix. This is the form of the system matrix used by Meyer-Arendt.

Image Reconstruction Methods Based on Block Circulant System Matrices

An iterative image reconstruction method used with an imaging system that generates projection data, the method comprises: collecting the projection data; choosing a polar or cylindrical image definition comprising a polar or cylindrical grid representation and a number of basis functions positioned according to the polar or cylindrical grid so that the number of basis functions at different radius positions of the polar or cylindrical image grid is a factor of a number of in-plane symmetries between lines of response along which the projection data are measured by the imaging system; obtaining a system probability matrix that relates each of the projection data to each basis function of the polar or cylindrical image definition; restructuring the system probability matrix into a block circulant matrix and converting the system probability matrix in the Fourier domain; storing the projection data into a measurement data vector; providing an initial polar or cylindrical image estimate; for each iteration; recalculating the polar or cylindrical image estimate according to an iterative solver based on forward and back projection operations with the system probability matrix in the Fourier domain; and converting the polar or cylindrical image estimate into a Cartesian image representation to thereby obtain a reconstructed image.
Owner:SOCPRA SCI SANTE & HUMAINES S E C

Field image tomography for magnetic resonance imaging

Field Image Tomography (FIT) is a fundamental new theory for determining the three-dimensional (3D) spatial density distribution of field emitting sources. The field can be the intensity of any type of field including (i) Radio Frequency (RF) waves in Magnetic Resonance Imaging (MRI), (ii) Gamma radiation in SPECT/PET, and (iii) gravitational field of earth, moon, etc. FIT exploits the property that field intensity decreases with increasing radial distance from the field source and the field intensity distribution measured in an extended 3D volume space can be used to determine the 3D spatial density distribution of the emitting source elements. A method and apparatus are disclosed for MRI of target objects based on FIT. Spinning atomic nuclei of a target object in a magnetic field are excited by beaming a suitable Radio Frequency (RF) pulse. These excited nuclei emit RF radiation while returning to their normal state. The intensity or amplitude distribution of the RF emission field g is measured in a 3D volume space that may extend substantially along the radial direction around the emission source. g is related to the 3D tomography f through a system matrix H that depends on the MRI apparatus, and noise n through the vector equation g=Hf+n. This equation is solved to obtain the tomographic image f of the target object by a method that reduces the effect of noise.
Owner:SUBBARAO MURALIDHARA

Power system transient stability simulating method based on implicit numerical integration

InactiveCN102609575ASmall amount of calculationReduced number of integration step iterationsSpecial data processing applicationsInformation technology support systemTruncation error (numerical integration)Transient state
The invention discloses a power system transient stability simulating method based on implicit numerical integration. Compared with an existing power system transient stability numerical simulation implicit trapezoidal integration method, the power system transient stability simulating method employs a power-angle integration formula with a smaller local truncation error, namely, enables a non-linear differential equation set for describing a power system transient process to be expressed as a linear portion and a non-linear portion. An accurate analysis expression of a state transition matrix is obtained by reasonably selecting a system matrix of the linear portion as a singular matrix, and a group of implicit integration formulas is obtained by leading linear integrable functions to be approximate to the non-linear portion of the differential equation set. The local truncation error of the power-angle implicit integration formulas of the generator refers to O (h5) which is larger than a local truncation error O (h3) of implicit trapezoidal integration, the calculated quantity of integration each time is equivalent to that of the implicit trapezoidal integration. By means of the high-precision implicit integration formulas, iteration times of each integration step under the same iteration precision condition are decreased, so that the simulated calculated quantity is remarkably decreased.
Owner:ZHEJIANG UNIV

A method for improving small disturbance stability after double-fed unit gets access to the system

A method for improving system small disturbance stability after double-fed unit gets access to the system belongs to the field of electric power system operation and control technology. A sensitivity analysis is adopted to optimize parameter, through making sensitivity analysis on the non-ideal dominant mode happens to the system to find out several nonzero elements that are most sensitive to this mode in system matrix; elements of state matrix is adopted to replace the elements of system matrix to make analysis so as to find out the most relevant parameter set; setting parameters change in the interval to observe track for the change of eigenvalues of corresponding mode and then balancing and optimizing system parameters comprehensively according to the change of eigenvalues. Without adding other control means, the present invention can improve dominant modal damping caused by selecting improper controller parameters or system parameters after double-fed unit gets access to the system without increasing cost; as this method is also highly targeted, exhaustive efforts for all the adjustable parameters of the system can be avoided, which not only greatly decreases workload, but also improves computational efficiency, so that it is very instructive.
Owner:WIND POWER TECH CENT OF GANSU ELECTRIC POWER

Field image tomography for magnetic resonance imaging

Field Image Tomography (FIT) is a fundamental new theory for determining the three-dimensional (3D) spatial density distribution of field emitting sources. The field can be the intensity of any type of field including (i) Radio Frequency (RF) waves in Magnetic Resonance Imaging (MRI), (ii) Gamma radiation in SPECT / PET, and (iii) gravitational field of earth, moon, etc. FIT exploits the property that field intensity decreases with increasing radial distance from the field source and the field intensity distribution measured in an extended 3D volume space can be used to determine the 3D spatial density distribution of the emitting source elements. A method and apparatus are disclosed for MRI of target objects based on FIT. Spinning atomic nuclei of a target object in a magnetic field are excited by beaming a suitable Radio Frequency (RF) pulse. These excited nuclei emit RF radiation while returning to their normal state. The intensity or amplitude distribution of the RF emission field g is measured in a 3D volume space that may extend substantially along the radial direction around the emission source. g is related to the 3D tomography f through a system matrix H that depends on the MRI apparatus, and noise n through the vector equation g=Hf+n. This equation is solved to obtain the tomographic image f of the target object by a method that reduces the effect of noise.
Owner:SUBBARAO MURALIDHARA

Image reconstruction methods based on block circulant system matrices

An iterative image reconstruction method used with an imaging system that generates projection data, the method comprises: collecting the projection data; choosing a polar or cylindrical image definition comprising a polar or cylindrical grid representation and a number of basis functions positioned according to the polar or cylindrical grid so that the number of basis functions at different radius positions of the polar or cylindrical image grid is a factor of a number of in-plane symmetries between lines of response along which the projection data are measured by the imaging system; obtaining a system probability matrix that relates each of the projection data to each basis function of the polar or cylindrical image definition; restructuring the system probability matrix into a block circulant matrix and converting the system probability matrix in the Fourier domain; storing the projection data into a measurement data vector; providing an initial polar or cylindrical image estimate; for each iteration; recalculating the polar or cylindrical image estimate according to an iterative solver based on forward and back projection operations with the system probability matrix in the Fourier domain; and converting the polar or cylindrical image estimate into a Cartesian image representation to thereby obtain a reconstructed image.
Owner:SOCPRA SCI SANTE & HUMAINES S E C

Automatic construction method and device of text proofreading error word library

The invention relates to an automatic construction method and device of a text proofreading error word library. The method comprises the steps of constructing a large-scale correct word library table,and numbering each word according to the order in the correct word library table; regarding each Chinese character in the word library of a computer system, constructing a series of word tables; creating a word relevancy system matrix table; sequentially enumerating each word in the correct word library table, sequentially replacing other Chinese characters for each Chinese character in each word, and calculating word matching similarities between correct words and error words after one Chinese character is replaced; ranking the values of the word matching similarities in a gradually decreasing mode, setting a similarity threshold value of word matching, and supplementing words with the similarity values larger than the threshold value to the error word library. The method can overcome the defects that in the prior art, error word table collection excessively relies on manual modes, the efficiency is low, the coverage surface is narrow, and the scale of the word library is limited; the accuracy of automatic text proofreading can be improved.
Owner:李晓妮

Specific fluorescent probe for recognizing fluorine ions and application of specific fluorescent probe

The invention discloses a specific fluorescent probe for recognizing fluorine ions and an application of the specific fluorescent probe, and belongs to the field of fine chemistry. The fluorescent probe is a 2-(2-hydroxycyclohexyl phenyl ketone) benzothiazole derivative. The 2-(2-hydroxycyclohexyl phenyl ketone) benzothiazole derivative and triethylamine are dissolved in tetrahydrofuran, acyl chloride is slowly dripped into the tetrahydrofuran in ice bath, and finally, purification is realized by silica gel chromatography to obtain the fluorescent probe. The fluorescent probe and a corresponding fluorine ion content detection process cannot be interfered by a biological system matrix and impurities, and can be used for quantitatively measuring fluorine ion content in various biological systems. The fluorescent probe has high specificity, can specifically realize silicon-oxygen bond breakage under the action of fluorine ions, is cheap and available, high in sensitivity and suitable for detecting the fluorine ion content in cells and can be obtained by chemical synthesis, the synthesis process is simple and practicable, and the fluorine ions are quantitatively measured by drawing a standard curve.
Owner:苏州新启材料科技有限公司

Robust H-infinity-based variable-gain decoupling control method

ActiveCN105182743AAchieving Steady State DecouplingAchieve approximate decouplingPosition/course control in three dimensionsAdaptive controlDecompositionSystem matrix
The invention discloses a robust H-infinity-based variable-gain decoupling control method. The objective of the invention is to solve the technical problem of little possibility to realize inter-channel decoupling control in wide-range flight of an aircraft. The method includes the following steps that: a longitudinal dynamics model of the aircraft is provided, wherein the model is characterized in nonlinearity, strong coupling, multi-variable performance and uncertainty; a decomposition problem of an original system is transformed to a robust H-infinity problem of an uncertain linear parameter-varying error system through variable decomposition and along-the-time path-varying linearization; the robust H-infinity problem of the uncertain linear parameter-varying error closed-loop system is transformed into a robust H-infinity problem of a corresponding certain system, and the convex polyhedron form of a system matrix can be obtained through adopting a tensor product model; and a limited number of linear matrix inequalities are solved based on the robust H-infinity theory, so that a variable-gain robust decoupling controller can be obtained. With the controller adopted, approximate decoupling of the system can be realized, and the approximate decoupling degree can be measured by the performance index gamma of H-infinity.
Owner:BEIHANG UNIV

High-strength ion exchange resin with double-channel macroporous structure and preparation method thereof

The invention discloses a high-strength ion exchange resin with a double-channel macroporous structure and a preparation method thereof. The high-strength ion exchange resin is prepared by polymerization of a styrene system and / or acrylic acid system matrix, a cross-linking agent and an initiator to generate a condensate, which forms a skeleton with a porous sponginess structure containing uniformly distributed macropores and micropores, under effects of two different pore forming agents. The preparation method is as below: mixing the matrix, the cross-linking agent, a macropore forming agent and a micropore pore forming agent, and heating; then adding the initiator, and mixing uniformly; adding the mixture into hot water, then stirring and adjusting the stirring speed, and carrying out an insulation reaction in the hot water; heating to 95 DEG C, and insulating and reacting for 3 h; washing the polymer with cooling water, drying and screening out polymer microballoons with appropriate granularity; moving out the pore forming agents through a distillation or extraction mode; and carrying out acidic or alkali treatment to obtain the high-strength ion exchange resin with the double-channel macroporous structure. The resin has high mechanical strength.
Owner:JIANGSU SUQING WATER TREATMENT ENG GROUP

Cable structure monitoring method based on long gauge optical fiber grating sensors

The invention discloses a cable structure monitoring method based on long gauge optical fiber grating sensors. The method comprises the following steps that a healthy monitoring system on the cable structure is laid out by utilizing a cable clamp, wherein the healthy monitoring system is composed of a plurality of long gauge optical fiber grating sensors arranged on the cable structure, and a strain signals monitored by the healthy monitoring system is collected through a signal collection system; an exciting hammer is adopted to hammer the node position where the cable structure lays out the long gauge optical fiber grating sensors; the signal collection system collects an impact signal and a long gauge strain time history in a vibration test; a system array based on an identification algorithm of a subsystem is identified, and multi-layered parameters of the cable structure is further identified; identification on cable force is conducted by utilizing identified frequency, and damage of the cable structure is identified and located according to identified formation and flexibility. According to the cable structure monitoring method based on the optical fiber grating sensors, the optical fiber grating sensors are applied to health monitoring of an inhaul cable, and thus stable and reliable monitoring means and method are provided for long-term monitoring and performance evaluation of the cable structure.
Owner:SOUTHEAST UNIV
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products