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180 results about "Principal direction" patented technology

Principal direction. A tangent direction at a point of a regular surface in which the normal curvature of the surface at that point attains an extremal value. Each point of a surface has either two principal directions, or else each direction is a principal direction (at a flat point and at an umbilical point ).

Lightweight thermoplastic composite including bi-directional fiber tapes

A lightweight fiber reinforced thermoplastic composite having an improved combination of flexural, impact, and heat distortion characteristics. The composite generally comprises a fiber reinforced thermoplastic core containing reinforcing fibers bonded together with a first thermoplastic resin in which the core has a first surface and a second surface and at least one first skin applied to the first surface. The first skin comprises one or more bi-directional continuous fiber tapes having a plurality of continuous fibers bonded together with one or more thermoplastic resins. The fibers in each first skin are arranged in a first principal direction and a second principal direction, with the fibers in each direction being aligned in a unidirectional orientation within the skin. The fiber reinforced composite of the invention includes embodiments wherein one or more tapes is utilized in which the bi-directional orientation of the continuous fiber tapes is present in at least one of the tapes, or is achieved through the use of two or more tapes having unidirectional continuous fibers. The invention is useful in the manufacture of automotive, rail, bus, marine, aerospace and construction articles in which the improved characteristics provide advantages over other materials utilized for such applications.
Owner:AZDEL INC

Fractured reservoir permeability tensor and anisotropy quantitative prediction method

The invention relates to the field of oil-gas field exploration and development, in particular to a fractured reservoir permeability tensor and anisotropy quantitative prediction method. On the basis of stress field numerical simulation, a static coordinate system and a dynamic coordinate system are integrated into a geodetic coordinate system by using the current occurrence of fractures, multiple groups of fracture permeability tensor quantitative prediction models are established, quantitative calculation formulas of the permeability principal direction and data are given, and the permeability of fractures in units in different directions is predicted by adjusting the rotation angle of the dynamic coordinate system. The fractured reservoir permeability tensor and anisotropy quantitative prediction method is based on strict mathematical algorithm derivation, a corresponding calculating program can be developed by using computer programming languages, fractured reservoir permeability tensor and anisotropy quantitative prediction is realized, the prediction cost is low, the operability is high, and the prediction result has certain guiding significance on determining the fault block permeability dominant direction, deploying and developing well patterns reasonably, and determining the spatial location relationship between an injection well and a producing well.
Owner:CHINA UNIV OF GEOSCIENCES (WUHAN)

Three dimensional earth pressure testing device and assembly computing method based on general earth pressure cells and rhombic dodecahedron

The invention provides a three dimensional earth pressure testing device based on general earth pressure cells and a rhombic dodecahedron. According to the device, six general earth pressure cells are fixed onto six surfaces, of which the normal vector quantities are uncorrelated, of the rhombic dodecahedron, so that the three dimensional earth pressure testing device is formed; grooves used for accommodating earth pressure cells are arranged on the surfaces of the rhombic dodecahedron with uncorrelated normal direction vector quantities; a conducting wire hole leading to the centroid of the rhombic dodecahedron is formed in the center of each groove; a conducting wire converging hole leading to the centroid is formed in each surface center of the rhombic dodecahedron except the grooves, so that six conducting wire holes and the converging holes converge at the centroid; meanwhile, a method for assembly and compute the three dimensional earth pressure testing device is provided. The invention has the effect that the three dimensional earth pressure testing device obtain, through testing, three principal stress of the earth pressure in the principal directions with measuring accuracy of 1.22 Rho, the measuring accuracy of three shearing stress is 0.71 Rho, the average measuring accuracy is 0.965 Rho, the safety storage of the engineering construction is improved, and the health condition of the engineering in later period can be effectively evaluated.
Owner:XINXIANG UNIV

Method for preparing integral turbine blade disc based on SiC fiber ceramic matrix composite material

The invention discloses a method for preparing an integral turbine blade disc based on a SiC fiber ceramic matrix composite material, which is used for solving the technical problem of the poor practicability of the existing integral turbine blade disc preparation method. The technical scheme is as follows. Firstly, a plane polar coordinate weaving method is adopted to prepare a turbine blade discprefabricated body unit layer, so that continuous SiC fibers are arranged in two principal stress directions in the warp direction and the weft direction. Then Z-direction puncture, sewing and die pressing are adopted to finish the shaping of the prefabricated body. A BN interface layer is prepared on the surface of the SiC fiber of the prefabricated body by utilizing a chemical vapor infiltration method. The prefabricated body of the turbine disc is pre-densified by adopting a chemical vapor infiltration process. The turbine disc blade is processed by adopting a cubic boron nitride or diamond special cutter on a multi-axis numerical control machine tool. Finally, an anti-oxidation coating is prepared. As the prefabricated body is provided with the continuous SiC fibers in two main principal directions in the warp direction and the weft direction, the bearing performance of the integral turbine blade disc is improved, the preparation period of the integral turbine blade disc is shortened, and the practicability is good.
Owner:NORTHWESTERN POLYTECHNICAL UNIV

User behavior anomaly detection system and method based on principal component analysis

The invention discloses a user behavior anomaly detection system and method based on principal component analysis, and belongs to the technical field of a computer. The system comprises a user behavior preprocessing module, a user behavior training module, a PCA module, a user behavior detection module and a user behavior anomaly processing module. The method comprises a user behavior training stage and a user behavior detection stage. The user behavior training stage is used for generating a user behavior anomaly threshold value. The user behavior detection stage is used for judging whether a real-time behavior is abnormal or not by employing the user behavior anomaly threshold value. According to the system and the method, the anomaly behavior of a user is detected by employing a PCA method,; the PCA is very sensitive to anomaly value change, the influence of the user behavior anomaly on a principal direction is very high, and therefore, a user behavior detection is more effective; no repeated operation exists in the detection process, therefore, the detection efficiency is improved, and the method is easy to realize; whether the real-time user behavior is abnormal or not is detected by employing the threshold value, and therefore, the detection is efficient and convenient.
Owner:NORTHEASTERN UNIV

Method and apparatus for deriving at least one audio signal from two or more input audio signals

A multidirectional audio decoder using an “adaptive” audio matrix derives at least one of a plurality of output audio signals from two or more directionally-encoded audio input signal streams (S1(α), S2(α), . . . SN(α), wherein α is the encoded angle of a source audio signal. Each output signal is associated with a principal direction β. In order to generate each output signal, a pair of intermediate signals (“antidominant” signals) are generated, constituting the antidominant signal for each of the two adjacent principal output directions of the decoder. The antidominant signal for any arbitrary principal (or “dominant”) direction is the combination of input signals having coefficients such that the combination goes to zero for that dominant direction. Amplitude control is applied to the two antidominant signals to deliver a pair of signals having substantially equal magnitudes that are additively or subtractively combined to provide the output audio signal associated with a principal direction. The pair of signals that are combined include passive matrix components. In an alternative embodiment, passive matrix components for the output signal are derived instead by applying the input audio signals to a passive matrix and by combining the passive matrix components with pairs of amplitude controlled versions of the antidominant signals that do not include passive matrix components. For sources from one direction at a time, there is little or no unwanted crosstalk into outputs that should be silent (ie., there is substantially no signal in outputs other than the two representing directions adjacent to the desired direction, except when the desired direction happens to correspond to that of an output, in which case there is a signal in substantially only that output).
Owner:DOLBY LAB LICENSING CORP

SAR (specific absorption rate) image registration method based on straight lines and area

ActiveCN103295232AAvoid problems with severe noise effectsReduce the impact of noiseImage analysisState of artComputation complexity
The invention discloses an SAR (specific absorption rate) image registration method based on straight lines and area, and mainly solves the problems of poor registering effect and high calculating complexity in the prior art. The SAR image registration method including the implementing steps of (1) inputting two SAR images and detecting straight lines in the two images through Hough conversion; (2), grouping the detected straight lines according to slope to acquire principal directions of the two SAR images, and calculating rotary parameter; (3), processing standard images and rotated images to be registered by the aid of an optical threshold segmentation method and through morphology corrosion and expansion to acquire a closed area; (4), utilizing an area centroid to calculate translation parameters; and (5), coinciding the standard images and the translationally rotated images to be registered to finish registration. The SAR image registration method based on the straight lines and area has the advantages that the SAR image registration method has small noise effect on registration of SAR images, is stable in SAR image segmentation results in a small water area and good in registration effect, high in speed and low in calculating complexity, and can be used for mode recognition, automatic navigation, computer vision and remote sensing image processing.
Owner:XIDIAN UNIV

Shape-intrinsic watermarks for 3-D solids

Umbilics of two surfaces are compared and it is determined from this comparison whether the suspect surface is a copy of the original surface based on the comparison. Comparing umbilics includes determining whether locations of the umbilics of the suspect surface match within a specified margin umbilics of the original surface, and determining whether pattern types of umbilics of the suspect surface match pattern types of corresponding umbilics of the original surface. A “weak” test may be performed, in which corresponding points on the two surfaces are compared, wherein the comparison of umbilics is performed if corresponding points of the two surfaces are located within a specified margin of each other. The points may be gridpoints on wireframes, which in turn may be based on lines of curvature of the surfaces. Comparing umbilics is performed if it is determined that each surface has at least one umbilic. Further still, an “intermediate” test may be performed which includes, for each surface, computing the principal directions of lines of curvature at each grid point. The computed directions of lines of curvature for corresponding gridpoints on the surfaces are compared. A determination is made as to whether the suspect surface is a copy of the original surface, based on the comparison.
Owner:MASSACHUSETTS INST OF TECH
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