42 results about "Boundary knot method" patented technology

Solutions to the problem of reversing seismic fault movements are formulated using a model based on elasticity theory, and using finite element and boundary element methods for generating a solution. The solution involves defining slip vectors from known formations in the fault and applying a space constraint restriction to traction values on the fault surface. The method may be applied in either 2D or 3D applications. The method is computationally fast enough to allow interactive fault reversal, and permits experimentation with various unfaulting scenarios so that a geologically acceptable solution is provided.

The invention belongs to the field of numerical analysis of multiple rows of rolling bearings of rolling mills, and concretely relates to a boundary element method for calculating load and pressure ofa rolling bearing under an elastohydrodynamic lubrication condition. The method includes introducing a bearing boundary element, a contact width Hertz correction theory and a plate element on the basis of a three-dimensional frictional elastic contact boundary element method to establish a bearing boundary element method; according to the theory of finite line contact elastohydrodynamic lubrication, deducing the equation of friction coefficient; establishing a boundary element method of a bearing under an elastohydrodynamic lubrication condition by coupling the bearing boundary element methodwith the finite line contact elastohydrodynamic lubrication theory; compiling a Fortran program of the bearing boundary element method under the condition of elastohydrodynamic lubrication. This method can be used to analyze the load and pressure distribution of multi-row rolling bearings, rolls and bearing blocks in full model. The load and pressure distribution of bearing under different lubrication conditions can be analyzed by changing the influence factors of roughness. Only surface unit division needs to be carried out on the bearing, the roller and the bearing housing, the unit division is few, and the calculation precision is high.

An area for layout of a plurality of I/O cells (called an “I/O area”) is provided in the peripheral portion of a chip and signal wirings for transferring test signals to the I/O cells are provided in the layout direction of the I/O cells. At least one empty cell provided in the I/O area at a position where I/O cells are not provided has a repeater circuit which constitutes a transfer path for the test signal. The repeater circuit receives the test signal and outputs the test signal. This structure provides a suitable semiconductor integrated circuit device adaptable for an ASIC or the like, which can adjust the delay of a test signal to be transferred along the chip's peripheral portion by suppressing an increase in the delay and degradation in waveform depression.

The invention discloses a boundary control method for restraining vibration of a flexible mechanical arm. The boundary control method comprises the steps that a flexible mechanical arm system is analyzed, and a mathematical model is established; then, a boundary controller of the flexible mechanical arm system is designed according to the mathematical model; stability analysis is conduced on the flexible mechanical arm system having the control function, the system movement state is stimulated, control parameters of the system are adjusted according to a simulation result, and the control parameters of the system are finally made to meet the design requirement. Thus, the vibration of the flexile mechanical arm in the working process can be effectively restrained; when the boundary controller is designed, the function of driving the flexible mechanical arm to arrive at a designated spot is added, and thus the position of the flexible mechanical arm can be tracked.

The invention discloses a boundary control method of restraining vibration of a flexible industrial conveyor belt, a flexible industrial conveyor belt system is analyzed and a mathematic model is established, the mathematic model is combined to design the adaptive feature of boundary disturbance of the flexible industrial conveyor belt system and a boundary controller, then stability of the flexible industrial conveyor belt system is subjected to simulated analysis, lastly, parameters of the flexible industrial conveyor belt system are adjusted according to a simulation result, and finally, the design requirements are achieved. According to the boundary control method, the vibration of the flexible industrial conveyor belt in a working process can be effectively restrained; meanwhile, the boundary control method has a certain adaptive feature on the boundary disturbance.

The invention relates to a method of reconstructing a circular stable sound source through the boundary element method in the signal reconstruction technical field. Through setting the sound source to be measured, a microphone array and a reference source microphone, the invention synchronously records the acquired reference signal and holographic measuring point sound pressure, obtains a reference phase from the reference signal, obtains the relative phase relation of the holographic measuring point source pressure acquired by the microphone array through the phase relation between the reference signal and the holographic measuring point source pressure, and finally obtains the self-spectrum correlated density vector of the sound source signal to be measured through reconstruction computing via the boundary element method. Through the reconstruction of the sound source signal on the holographic measurement surface acquired by the microphone array, the method can analyze the sound source with random shape and obtain the three-dimensional spectrum correlated density distribution of the sound source. Compared with the traditional method of identifying the sound source through the near-field acoustic holographic technology, the method can be applicable to the circular stable sound source with breakthrough on the requirements of the shape of the sound source.

The invention relates to an indeterminate harmonic flow calculation method applicable to distributive power supply access. The method concretely comprises the following steps of firstly, for a distributive power supply with the fluctuation on the output power, performing modeling on the basis of a measuring sample by using the output power of a reverse cloud model generator on a gird integration node; then, solving the power prediction range of the DG gird integration node according to the 3 Delta range of a positive cloud model; then, on the basis of the obtained power range, performing indeterminate harmonic flow calculation by combining a boundary flow method; solving the power grid harmonic flow distribution; finally, judging whether the harmonic content of each node of the power grid is in a safe range or not according to the node voltage total harmonic distortion factor result. The method provided by the invention has the advantages that better inclusivity is realized on the fluctuation data; in addition, under the condition of the same operation goal and conditions, the calculation efficiency of the provided calculation method is much higher than that of a Monte Carlo method; the calculation efficiency is identical to the calculation efficiency of a probability flow method.

A system for detecting and diagnosing lung neoplasms on CT images is provided. The system consists of a lung parenchyma segmentation module, a candidate nodule detection module and a candidate nodulediagnosis module. In the lung segmentation module, the original CT image is morphologically denoised, then the binary segmentation is performed by the optimal threshold method, the initial boundary isextracted by the boundary tracking method, the boundary is repaired by the boundary matching repair algorithm, and finally the lung parenchyma is segmented by the flood filling algorithm. In the candidate nodule detection module, the candidate nodule detection algorithm based on ring filter and the candidate nodule detection algorithm based on threshold are combined. The detection results will include a large number of false positives. First, the rule method is used to eliminate the false positives, and then the fuzzy super-box neural network based on K-means clustering algorithm is used as asystem classifier for the diagnosis of candidate nodules. This system provides a good support for doctors to diagnose lung cancer.

The invention discloses a boundary control method for anti-saturation of a flexible Timoshenko beam manipulator. The method comprises the steps that the dynamic characteristics of the flexible Timoshenko beam manipulator system are acquired; a flexible Timoshenko beam manipulator system model is constructed according to the dynamic characteristics; a boundary controller is constructed according tothe flexible Timoshenko beam manipulator system model; the stability of the flexible Timoshenko beam manipulator system is verified under anti-saturation control; MATLAB simulation software is used to digitally simulate the flexible Timoshenko beam manipulator system to acquire a simulation result; according to the simulation result, whether the control effect of the flexible Timoshenko beam manipulator system to which a control action is applied meets a preset requirement is verified; and if the control effect does not meet the preset requirement, the gain parameter of the boundary controller is adjusted according to the simulation result, so that the boundary controller has better anti-saturation control and tracking performances. The boundary control method provided by the invention can realize stable and accurate tracking and control of the manipulator.

The invention discloses an immersed boundary implicit iterative solving method meeting no-slip boundary conditions and continuity conditions; the method mainly comprises the steps of using a viscous incompressible flow N-S control equation, expanding a momentum equation along a feature line to perform time discretization, using a finite element method to perform spatial discretization, and adding additional body force to the discretized control equation; using a direct force method to solve the additional body force so that interpolation speed on the boundary is equal to expected speed distribution; when a fractional step method is in use, dividing the additional body force into two parts according to whether it is coupled to pressure, and solving the two parts respectively; performing speed correction in iterative computation of the additional body force and pressure to obtain final flow field distribution. The problem of an existing immersed boundary method that no-slip boundary conditions and continuity conditions cannot be met at same time is solved; after the additional body force is divided into two parts, the cost of solving a component item uncoupled to the pressure is effectively reduced, and the computing efficiency of the immersed boundary method is improved.

The invention discloses an immersion boundary control method used for underwater obstacle avoidance of a multi-joint snake-like robot, and belongs to the field of robot control. The implementation method comprises the steps that the lattice Boltzmann method is introduced to replace a traditional Navier-Strokes equation for solving fluid and in second order partial differential equation simulation,and starting from the angle of probability statistics, the macroscopic and microcosmic relation and the discrete and continuous relation are solved from different angles. The lattice Boltzmann methodis simple in calculation, and parallel realization is easy. When complex boundary conditions are treated, macroscopic and microcosmic conversion can be achieved, a flexible multi-joint snake-like robot force source model is set up through an immersion boundary method, Euler variables in a fluid field are adopted for controlling the fluid dynamic state, the motion boundary of the multi-joint snake-like robot is controlled through the Lagrange variable of the force source model, a smooth Delta approximate function is used for controlling the interaction of nonlinear fluid field force and the force source boundary through distribution node force and the difference value speed, and nonlinear control of the multi-joint snake-like robot is achieved.

The invention discloses a boundary control method, a system thereof, a low frequency positioner and an identification card. The boundary control method comprises the following steps: the identification card provided on a supervised object identifies whether the identification card enters into a boundary area scope or not according to whether inductive electromotive force is generated or not, and the boundary area scope is a magnetic field scope generated by the low frequency positioner; according to an identification result, when entering into the boundary area scope, the identification card sends a report message of entering into a boundary area to a high frequency base station, and the report message comprises card identification information which only identifies the identification card; the high frequency base station forwards the report message to a control center, so that the control center generates alarm information that the identification card enters into the boundary area scope. According to an embodiment of the invention, specific personnel or article is effectively controlled to enter into or leave a specific area, and effective supervision of the specific personnel or article is realized.

The invention discloses a boundary scan test method and a boundary scan test device for reducing noise. The method comprises the following steps of: generating the original test vector according to test contents; processing the original test vector to acquire a new test vector; applying the new test vector to a tested object to acquire a response vector at the same time; extracting the response vector corresponding to the newly-added test vector; and performing diagnosis on the boundary scan test by using the extracted response vector as a final effective analysis vector. The device comprises an original test vector generation module, a new test vector generation module, a test implementation module, an effective response vector acquisition module and a diagnosis analysis module. The method and the device can effectively reduce the noise caused by the boundary scan test, improve the accuracy of the test, are simple to implement, do not need to add any test hardware and have high fault coverage rate.

The invention provides a conversion device and a conversion method for electroencephalogram record references; the conversion device and the conversion method are used for converting references of the left ear and the right ear into a uniform infinite reference respectively, and belong to the technical field of biological information. The conversion method provided by the invention is implemented by the following steps of determining spatial positions of electroencephalogram collection electrodes, a to-be-detected head model and equivalent distributed source model information; computing transfer matrixes G and Glr by a boundary element method; computing generalized inverse Glr+ of Glr by a singular value decomposition method, and computing a standardized matrix Rlr according to Rlr=GGlr+; finally, working out electroencephalogram data V minute=Rlr/Vlr taking an infinite point as the uniform reference according to original electroencephalogram data Vlr respectively referenced by the left ear and the right ear. Compared with previous methods, the conversion method has the advantages that the influence brought to electroencephalograms by the electrode movement of the left ear and the right ear in original record data can be eliminated; meanwhile, signals of the electrodes of the left ear and the right ear and proximity electrodes are reduced, and therefore unprecedented exchange between bipolar lead and unipolar lead is realized.

The invention provides a boundary treatment method of coupling a direct-current resistivity element-free method with a finite element method. The boundary treatment method includes the steps of building a small-range element-free method area omega 1 to a two-dimension geoelectric model, calculating by the element-free method for the area, covering the element-free method area omega 1 with regularly distributed rectangular or parallelogram background grid to obtain an element-free method equation set of the area; subdividing the periphery of the element-free method area omega 1 by finite element method grid which is capable of rapid expansion, building a large-enough finite element method area omega 2 which meets requirements of first class of boundary conditions, calculating by the finiteelement method to obtain a finite element equation set of the area; combing the equation sets of the two areas and solving to obtain parameter of the apparent resistivity of an observation point. Themodels can be discrete on the basis of arbitrary node distribution by the method, the boundary treatment method has high adaptability to any complex geoelectric models, and calculation efficiency of forward modeling in the conventional direct-current resistivity element-free method is improved since boundary treatment is carried out by means of the finite element method.

A method of numerically exploiting symmetry in a coupled electromechanical analysis, while still preserving the previously established advantages of the hybrid BEM/FEM approach for performing such analyses without exploiting symmetry is disclosed. The present invention allows advantageous acceleration techniques, which maximize analytical efficiency, to be employed for the analysis of systems with moving or deformable parts. The illustrative embodiment of the present invention is particularly applicable to simulating the physical behavior of MEMS (microelectromechanical system) devices and other complicated multi-domain devices.

The invention provides a boundary tracking method and device. The method comprises the steps of: extracting a boundary point set; selecting a first seed point from the boundary point set; looping a first tracking step until a first ending condition is met, wherein the first tracking step comprises finding a pixel point meeting a first target condition in an adjacent area of the first seed point, using the pixel point as a first target point and using the first target point as an updated first seed point, the first target condition includes that the point belongs to the boundary point set and is not used as the first target point in the first tracking step executed before, and the first ending condition includes that no pixel point meeting the first target condition is found in the adjacent area of the first seed point; and using the successively found first target points or first seed points as boundary points, tracked in sequence, of a first target area. According to the invention, the boundary point set is firstly extracted, then boundary tracking is carried out according to the boundary point set, and repeated scanning is not needed, so that the workload is reduced.

The invention discloses a mixed absorbing boundary condition method based on Higdon cosine type weighting, which belongs to the field of forward simulation modeling of seismic exploration, and comprises the following steps of: carrying out a finite-difference numerical simulation by adopting an acoustic wave equation of two-dimensional scalar to divide the whole study area into a central wave field area, a transition area and a boundary area; solving a two-way wave equation of acoustic wave of two-dimensional scalar to obtain a two-way wave field in the central wave field area and the transition area; solving a second-order Higdon absorbing boundary equation to obtain a one-way wave field in the transition area and the boundary area; and performing cosine-type weighted overlay on the two-way wave field and the one-way wave field in the transition area to obtain a final wave field. The mixed absorbing boundary condition method based on Higdon cosine-type weighting adopts a cosine-type weighted overlay mode to construct a mixed absorbing boundary, so that the inner boundary is better coupled with the central wave field area, thereby effectively suppressing the inner boundary reflection of the mixed absorbing boundary.

The invention relates to a boundary test circuit, a memory and a boundary test method. The boundary test circuit in an embodiment of the invention comprises a plurality of boundary register circuits.One end of each boundary register circuit receives an initial test signal, and the other end thereof transmits the initial test signal to a next boundary register circuit. The boundary test circuit also comprises a plurality of state control circuits, wherein an input terminal of each state control circuit receives an initial test signal stored in the boundary register circuit, a control terminalof the state control circuit receives a state control signal, and an output terminal of the state control circuit sends a real-time test signal to an integrated circuit to be tested; the real-time test signal is the signal with the same phase or opposite phase as the initial test signal. Boundary test circuits provided by embodiments of the present disclosure may improve test efficiency and test flexibility.

The present invention relates to a novel velocity correction method for a projected immersed boundary method, belonging to the technical fields of computational fluid dynamics and fluid-solid coupling simulation thereof. The velocity correction method of the present invention comprises: A) invoking a mesh generation module, wherein two meshes are used: an Eulerian mesh in a fluid field region, and a Lagrangian mesh in a solid boundary region; B) invoking a flow field velocity prediction module to obtain a predicted value of the flow field region; C) invoking an Eulerian mesh point attribute determining module to determine whether an Eulerian mesh point belongs to a solid inner region or a solid outer region; D) invoking a flow field velocity correction module to update a flow field velocity; E) invoking a result output module to output a force acting on a fluid-solid boundary and flow field information to a file, so that reading and displaying can be performed by the background; and F) determining whether to end calculation. The novel velocity correction method for the projected immersed boundary method eliminates the complex interpolation operation for resolving the velocity of the near-wall region in the conventional projected immersed boundary method, thereby saving computing resources and improving computing efficiency.

The invention discloses a ship boundary control method, which is used for controlling a ship without a power supply and is based on a ship boundary control system, the ship boundary control system comprises a management platform and a ship terminal fixedly connected to a ship body, and the ship terminal comprises a solar charging module, a positioning module, a communication module and a control module; the solar charging module is used for supplying power to each module; the positioning module is used for acquiring and sending positioning information to the control module; the communication module is used for receiving and forwarding the positioning information to the management platform and forwarding the parameter setting instruction to the control module; the control module is used forreceiving the parameter setting instruction, storing parameter values in the parameter setting instruction and controlling the positioning module and the communication module according to the parameter values; the management platform is used for receiving and processing the positioning information to determine a distance value between the ship and the boundary, setting a parameter value accordingto the distance value and sending the parameter value to the communication module; and the management platform judges whether to give an alarm or not according to the distance value.

The invention provides a boundary nesting method based on remote sensing interpretation. The boundary nesting method comprises the following steps of vector data separation, layer conversion, data processing, line element extension, point layer conversion and boundary nesting. The invention further relates to a boundary nesting system based on remote sensing interpretation, a storage medium and electronic equipment. According to the method, element separation is carried out on vector data after remote sensing interpretation to form an automatically generated element layer and an artificially sketched layer; according to the method, the automatically generated element graph layer is converted into the line graph layer, the graph layer obtained after data processing is conducted on the linegraph layer is combined with the manually sketched graph layer, the surface vector graph layer obtained after nesting is completed is obtained, full-automatic processing is achieved, the boundary nesting efficiency is improved, and the labor cost is saved.