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445 results about "Vector field" patented technology

In vector calculus and physics, a vector field is an assignment of a vector to each point in a subset of space. A vector field in the plane (for instance), can be visualised as a collection of arrows with a given magnitude and direction, each attached to a point in the plane. Vector fields are often used to model, for example, the speed and direction of a moving fluid throughout space, or the strength and direction of some force, such as the magnetic or gravitational force, as it changes from one point to another point.

Simulation gridding method and apparatus including a structured areal gridder adapted for use by a reservoir simulator

A Flogrid Simulation Gridding Program includes a Flogrid structured gridder. The structured gridder includes a structured areal gridder and a block gridder. The structured areal gridder will build an areal grid on an uppermost horizon of an earth formation by performing the following steps: (1) building a boundary enclosing one or more fault intersection lines on the horizon, and building a triangulation that absorbs the boundary and the faults; (2) building a vector field on the triangulation; (3) building a web of control lines and additional lines inside the boundary which have a direction that corresponds to the direction of the vector field on the triangulation, thereby producing an areal grid; and (4) post-processing the areal grid so that the control lines and additional lines are equi-spaced or smoothly distributed. The block gridder of the structured gridder will drop coordinate lines down from the nodes of the areal grid to complete the construction of a three dimensional structured grid. A reservoir simulator will receive the structured grid and generate a set of simulation results which are displayed on a 3D Viewer for observation by a workstation operator.
Owner:SCHLUMBERGER TECH CORP

Fingerprint recognition system

A method of analyzing and recognizing fingerprint images that utilizes vector processing of a vector field that is defined as the tangential vector of the fingerprint ridge curves is disclosed. The raw fingerprint image is divided into blocks, filtered to remove noise, and the orientation direction of each block is found. This allows the ridge curves to be enhanced and approximated by piece-wise linear approximations. The piece-wise linear approximations to the ridge curves allow the minutiae to be extracted and classified and a fingerprint minutiae template to be constructed. An enrollment process gathers multiple fingerprint images, creates fingerprint minutiae templates corresponding to the acquired fingerprint images, and stores the templates and other data associated with the respective individual or the enrolled fingerprint in a fingerprint database. In an identification process, an unknown raw fingerprint image is obtained via a fingerprint scanner and processed similarly to the enrollment process such that the fingerprint minutiae template of the unknown fingerprint is compared to one or more previously enrolled fingerprint minutiae templates. The identity of the individual associated with the unknown fingerprint is thereby ascertained. In addition, live finger detection can be accomplished in conjunction with the verification or identification process through analysis of the fingerprint image thus enhancing the security of the overall system.
Owner:GEOMETRIC INFORMATICS INC

Improved VFH algorithm-based positioning and obstacle avoidance method and robot

ActiveCN103926925ASolve the obstacle avoidance path planning problemPosition/course control in two dimensionsLaser rangingHome environment
The invention provides an improved VFH algorithm-based positioning and obstacle avoidance method and robot. According to the improved VFH algorithm-based positioning and obstacle avoidance method and robot, on the basis of an improved vector field histogram method and a scan matching algorithm, environmental information is acquired by the adoption of a laser range-finder sensor, and the pose error brought by speedometer is amended by the adoption of the polar coordinate scan matching algorithm. After robot positioning is finished, environmental information is rasterized, an obstacle is expanded according to the relationship between the robot and the obstacle and considering the sensing uncertainty of a movable robot and the real size of the robot, an original polar coordinate histogram is built, the free walking area and the obstacle avoidance area are acquired, a binary polar coordinate histogram is acquired through the definition of two threshold values, a shielding polar coordinate histogram is built through estimating the movement trail of the movable robot, and finally, the cost function is introduced to determine the best movement direction of the robot so as to solve the problem of shielding route planning of the movable robot in a home environment.
Owner:江苏久祥汽车电器集团有限公司

Depth map coding method and device

The invention provides a depth map coding method and a device. The depth map coding method includes establishing a plurality of partition lines which are used for performing wedge-shape partition to a depth macro block, and forming the partition lines into a partition set; using an intra coding mode to code the depth micro block to obtain a first rate-distortion cost value; judging whether an inter coding mode is used for coding the depth micro block and using the inter coding mode to code the depth micro block to obtain a second rate-distortion cost value if the inter coding mode is used for coding the depth micro block; and continuing judging whether the depth micro block contains a discontinuous motion vector field and using a geometric partitioning coding mode to code the depth micro block if the depth micro block contains the discontinuous motion vector field, wherein the geometric partitioning coding mode includes selecting an optimal partition line to partition the depth micro block to obtain a first depth subdomain and a second depth subdomain and subjecting the two subdomains to predictive coding to obtain a third rate-distortion cost value; and comparing the rate-distortion cost values in different coding modes so as to select the coding mode with the minimum rate-distortion cost value for coding the depth micro block. According to the depth map coding method and the device, depth map compression efficiencies are improved, and coding complexities are reduced.
Owner:TSINGHUA UNIV +1

Vector-field-based small-sized unmanned plane wind-field anti-interference self-adaptive control method

The invention relates to a vector-field-based small-sized unmanned plane wind-field anti-interference self-adaptive control method, which relates to track design, establishment of track control vector field and design of slip-form variable structural controller of small-sized unmanned plane scientific research task. The motion of a small-sized unmanned plane is simplified to plane control and trans-lateral control through the plan of the scientific research task, the plane track plan is realized on the basis of a transitional connection point principle, and an expected complicated track is decomposed into a series of expected tracks consisting of circle arc sections with different circle centers and radiuses and straight sections; then a track control vector field of each expected track section is respectively established for the decomposed straight sectional expected track and the decomposed circle arc sectional expected track on the basis of the position error between the current position of the small-sized unmanned plane and the expected track; and the high-precision track control of the small-sized unmanned plane under the wind interference environment can be realized through the slip-form variable structure self-adaptive control method. The method has the advantages of good real-time performance, fast dynamic parameters, strong adaptability to the wind field interference and the like, and can be used for the high-precision control of the small-sized unmanned plane in a complicated environment.
Owner:BEIHANG UNIV

Quick motion estimation method of multi-view video coding

The invention discloses a quick motion estimation method of multi-view video coding, comprising the following steps of: carrying out spatial median filtering on a motion vector field of coded frames of adjacent views; calculating an overall parallax vector between the current view and the adjacent view by using a parallax vector field of the coded frame of the current view; selecting a reference motion vector from the filtered motion vector field by using the overall parallax vector; selecting a searching center of motion estimation by using the reference motion vector and the spatial motion vector of adjacent estimated blocks; selecting the searching range of the motion estimation by using the deviation degree of the searching center and the reference motion vector; and carrying out the final motion searching in the searching range, selecting the final motion vector of the current block, and finishing the selection of the final motion vectors of all blocks by using the same method and finishing the motion estimation of the multi-view video coding. The method is suitable for the motion estimation of the multi-view video encoding and can effectively reduce the calculation amount of the motion estimation and synchronously maintain the coding rate distortion performance.
Owner:ZHEJIANG UNIV

Complex scene-based human body key point detection system and method

The invention discloses a complex scene-based human body key point detection system and method. The method comprises the following steps of: inputting monitor video information to obtain a single-frame static map and a multi-frame optical flow graph; extracting features of the single-frame static map through a convolution operation so as to obtain a feature map, and in order to solve influences, on personnel target detection, of interference targets under complex scenes, judging a practical confidence coefficient and a preset confidence coefficient of the feature map by adoption of a personneltarget detection algorithm so as to obtain a discretized personnel target surrounding box; and carrying out optical flow overlapping on the multi-frame optical flow graph to form a two-dimensional vector field; extracting features in the discretized personnel target surrounding box to obtain a feature map, obtaining key points and association degrees of parts, generating a part confidence map foreach part of a human body by utilizing a predictor, and accurately detecting human body key points through the part confidence map and the two-dimensional vector field. The system and method are usedfor human body key point detection under complex scenes so as to realize accurate detection of personnel target key points.
Owner:CHINA UNIV OF PETROLEUM (EAST CHINA)

Correspondence between n-dimensional surface: vector fields that are defined by surfaces and that generate surfaces which preserve characteristics of the defining surfaces

Techniques for finding a correspondence between a source object and a target object, the objects having n>2 dimensions, such that a vector field based on the correspondence generates objects which tend to preserve the characteristics of both the source object and the target object. The techniques result in vector fields which maximize the generated object's similarity to the target object while minimizing structural changes to the source object. Minimization of structural changes is done by associating directional spring functions with points in the source object and finding a vector which generates an object for which changes in the directional spring functions are minimized. Further included are techniques for reducing the computational cost of finding a correspondence by making a set of pairs of increasingly-simplified representations of the source object and the target object and then finding pair vector fields for the pairs, beginning with the most simplified pair and ending with the original representations of the source object and the target object. The increasingly-simplified representations have the property that they preserve the large-scale structure of the original representations of the source object and the target object. The pair vector field for a given pair is found by extending the pair vector field found for the next simpler pair so that it applies to the pair's source object and then using the extended pair vector field as the initial vector field in finding the pair vector field. The techniques may be applied to images and to surfaces in which color is represented by means of additional dimensions. Vector fields found using the techniques may be used to generate objects belonging to a class of objects defined by the source object and at least the target object.
Owner:THE UNITED STATES OF AMERICA AS REPRESENTED BY THE SECRETARY OF THE NAVY

Autonomous navigation guidance method used for pilotless plane

The invention discloses an autonomous navigation guidance method used for a pilotless plane, which comprises a fairway planning method based on a speed vector field and a track tracking guidance method based on nonlinear navigation logic guidance law. The fairway planning method is characterized in that the flying area of a pilotless plane is regarded as the area of a speed field; a hauling field is generated at a target point in the area and generates the hauling speed on a planning point; an evasion field and a guide field are generated in a threat area and generates evasion speed and guide speed on the planning point; under the action of planning resultant speed, the movement track of the planning point is a fairway to be planned. The track tracking method is characterized in that a nonlinear navigation logic guidance command is given according to a given track by combining with the current position, the attitude information and the detection step length of the pilotless plane; a nonlinear guidance command is converted into a roll angle command by the conversion relation between accelerated speed and a roll angle; and the track tracking is realized by a flight control system. The invention has simple realization and good real-time performance and has very strong practical application prospect.
Owner:NANJING UNIV OF AERONAUTICS & ASTRONAUTICS

Rotating element sheet material with reversible highlighting

A kit comprising rotating element sheet material, a highlighting implement, and an erasing implement, a binder, and a method of use. The rotating element sheet material comprises a plurality of first rotatable elements and a plurality of second rotatable elements disposed in a substrate. Each first rotatable element in the plurality has a first collection of responses to incident electromagnetic radiation of interest. One response in the first collection renders the first rotatable element transparent-clear to incident electromagnetic energy of interest, and a second response renders the first rotatable element opaque to incident electromagnetic energy of interest. The first rotatable element also exhibits a first work function. Likewise, each second rotatable element has a second collection of responses to incident electromagnetic radiation of interest. A first response in the second collection renders the second rotatable element transparent-clear to the incident electromagnetic energy of interest. A second response renders the second rotatable element transparent-colored to the incident electromagnetic energy of interest. The second rotatable elements also exhibit a second work function that is less than the first work function. The addressing implement introduces a vector field in a first direction in the substrate where the vector field has a magnitude greater than the second work function and less than the first work function. In addition, the erasing implement introduces a vector field in a second direction in the substrate where the vector field has a magnitude greater than the second work function and less than the first work function. The binder is configured to accommodate the rotating element sheet material, the highlighting implement, and the erasing implement.
Owner:E INK CORPORATION

Fingerprint recognition system

InactiveUS20050157913A1Improve securityRidge curves to be enhancedMatching and classificationPattern recognitionMinutiae
A method of analyzing and recognizing fingerprint images that utilizes vector processing of a vector field that is defined as the tangential vector of the fingerprint ridge curves is disclosed. The raw fingerprint image is divided into blocks, filtered to remove noise, and the orientation direction of each block is found. This allows the ridge curves to be enhanced and approximated by piece-wise linear approximations. The piece-wise linear approximations to the ridge curves allow the minutiae to be extracted and classified and a fingerprint minutiae template to be constructed. An enrollment process gathers multiple fingerprint images, creates fingerprint minutiae templates corresponding to the acquired fingerprint images, and stores the templates and other data associated with the respective individual or the enrolled fingerprint in a fingerprint database. In an identification process, an unknown raw fingerprint image is obtained via a fingerprint scanner and processed similarly to the enrollment process such that the fingerprint minutiae template of the unknown fingerprint is compared to one or more previously enrolled fingerprint minutiae templates. The identity of the individual associated with the unknown fingerprint is thereby ascertained. In addition, live finger detection can be accomplished in conjunction with the verification or identification process through analysis of the fingerprint image thus enhancing the security of the overall system.
Owner:GEOMETRIC INFORMATICS INC
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