198 results about "Theoretical methods" patented technology

The invention discloses a DOA (Direction-of-Arrival) estimation method based on grid-less compressive sensing in the background of super-Gaussian noise, which comprises the steps of firstly determining an antenna array signal model, that is, receiving signals through a linear antenna array with the number of array elements being M and the spacing between the array elements being equal, selecting anorm of lp to perform constraint according a noise distribution type measured in the actual environment, then determining a function expression for solving a noiseless signal x, describing a problemof recovering the noiseless signal x into a problem of minimizing an atomic norm, and solving by adopting a theoretical method of semi-definite programming; then solving a primitive solution accordingto an ADMM algorithm, then solving a dual solution z^, finally solving the DOA, enabling the DOA to more approach to an angle support set of the primitive signal so as to complete DOA estimation. According to the invention, a noise item is effectively constrained by adopting an appropriate norm through using statistical characteristics of the noise, and finally the angle support set of the primitive signal is solved by using a relation between the primitive solution and the dual solution so as to achieve effective and accurate DOA estimation.

The invention discloses a fluctuation quantity method-based user side harmonic emission level practicality estimation method, belongs to the field of power quality harmonic treatment, is used for dividing rights and liabilities of harmonic pollution on a power supply side and an electricity side and belongs to a theoretical method practicality technology. The invention provides a complete processfor estimating the user side harmonic emission level by employing a fluctuation quantity method, provides a method for quantizing deviation between a power supply side harmonic impedance amplitude estimated value and an actual value, provides power supply side harmonic impedance amplitude estimated value accuracy for engineering, and easily and quantitatively judges whether the estimated value meets the requirement on engineering accuracy. In the method, various problems which possibly exist in actual engineering are considered theoretically. The conception of the time-varying dynamic phasor-based fluctuation quantity method is stated, the conventional harmonic impedance estimated value algorithm is improved, the least squares fitting algorithm which is wider in applicability and higher in accuracy is provided to estimate power supply side harmonic impedance; therefore, a practical flow more accords with actual operating conditions of a power system.

The invention discloses a selection method for the economic goal-optimized self-adaptive backoff of a chemical process predictive control system, which comprises the following steps: determining an economic goal of an enterprise production unit, establishing a variable steady-state optimization constraint relationship of a control unit, determining production variable operating restrictions, obtaining an LQG performance index based on the relationship between control and output, adjusting weight to construct a discrete point set based on the relationship between control and output variance, fitting a nonlinear variance adjusting reference, solving an optimization proposition to determine optimal set values and optimal backoff values for control and output, and automatically refreshing thesettings of the predictive control device based on changes of production. The method can avoid the blindness of the experience set value of the enterprise production device predictive control goal, the conservatism of the manual backoff value setting and the imperfection and the infeasibility of the present MVC reference theoretical method in the physical production process, becomes a self-adaptive optimization and backoff strategy which can be practically put into service in the chemical process, raises the production yield, saves energy and reduces emission and improves economic benefits ofthe enterprise to a greater extent.

The utility model relates to an active control test platform and a method for vibration of a near space aircraft model. The test platform leads an aircraft model distributed and stuck with a piezoelectric sensor and an actuator to be hung on an aluminum alloy outer framework, and is connected with a function signal generator of a power amplifier to drive an exciter fixed on the aluminum alloy outer framework and lead the aircraft model connected with the exciter to generate a vibration response; and a vibration response signal is collected by the piezoelectric sensor, and is outputted on the power amplifier and acted on the piezoelectric actuator through the operation of a computer inserted with a data acquisition and output card. The active control test platform has the characteristics of convenient composition, simple structure, and good expandability. The method can provide experimental verification realization means for the active control method for the vibration of the near space aircraft model, and provide technical realization supports for exploring the further practical applications of relevant control theories and methods.

A method of automating security risk assessment and management and corrective feedback with a cost-optimized allocation plan is disclosed. The method, operable in a computer system, includes presenting an on-line survey questionnaire and receiving, in response to the on-line survey questionnaire, a user-provided answer. The method further includes extracting data from the computer system and calculating, in response to the user-provided answer and the extracted data, a security risk. The method also includes producing, in response to the security risk, the cost-optimized allocation plan. The data and the user-provided answer are recorded in a data repository. The cost-optimized allocation plan is produced using a game-theoretical approach. The cost-allocation allocation plan includes changes to break even a cost differential of an expected cost of loss (ECL), and further assigns realistic market-oriented mitigation costs to each line of action for the user's computer or system.

A method of designing a ferritic iron-base alloy having excellent characteristics according not to the conventional trial-and-error technique but to a theoretical method, and a ferritic heat-resistant steel for use as the material of turbines and boilers usable even in an ultrasupercritical pressure power plant. Specifically, the d-electron orbital energy level (Md) and the bond order (Bo) with respect to iron (Fe) of each alloying element of a body-centered cubic iron-base alloy are determined by the Dv-Xalpha cluster method, and the type and quantity of each element to be added to the alloy are determined in such a manner that the average Bo value and average Md value represented respectively by the following equations:coincide with particular values conforming to the characteristics required of the alloy; wherein Xi represents atomic fraction of an alloying element i, and (Bo)i and (Md)i represent respectively the Bo value and Md value of the element i. Preferably, the average Bo value and average Md value are, respectively, in the ranges of 1.805 to 1.817 and 0.8520 to 0.8628.

The invention discloses a method for constructing a protection big data fault characteristics system based on wave recording and scanning technology. The method comprises the following steps: through the decoding of a wave recording file, accessing the waveform data of all sampling points; calculating the valid values and determining whether adjacent waves experience mutations or not; for the unit experiencing mutations in their valid values, using the slope mutations of the sampled values prior to or after the unit to determine the accurate mutation point and to determine the fault time; extracting the local characteristics quantity of the voltage and current waveform in the wave recording data; representing in multiple dimensions the characteristics information extracted from the data window given on the waveform; and using the fault time as the critical point to form local characteristics quantities at different times in the scanned waveform data prior to and after the fault and to construct a complete fault characteristics system. According to the invention, in multiple perspectives and dimensions, fault characteristics data are excavated and extracted, and based on the requirement of a protection big data analyzing platform and a big data theory, a fault characteristics system structure is formed, which can ensure the realization of higher-level of application functions of the protection big data in a power grid system.

The invention discloses a method for calculating a work load based on beam surface strain values measured by optical fiber sensors, and aims to utilizing an optical fiber Bragg grating (FBG) technology to measure the beam surface internal strain values and then obtain real-time planar applied bending or torsion work load data. According to the invention, FBG strain sensors are utilized and are pasted on a beam structure at certain intervals, so that the beam is divided into a plurality of regions. By adopting the method, the torque, the bending moment and the shearing force of the cross section where the optical fiber sensor is arranged are calculated, and then the work load value of the region is calculated by utilizing the shearing forces of two adjacent cross sections. Specific embodiment schemes are provided by invention for verifying the precision of the method. Compared with other methods for measuring the work load of the beam in the prior art, the method provided by the invention is interference resistant, time-saving, cost-saving and high in efficiency.

The invention provides an inertia gravity combined navigation semi-physical simulator which is a device suitable for the theoretical method and engineering application research of an inertia/gravity combined navigation system. A path generator generates ideal data inputted to an inertia measuring unit, a gravimeter simulator, a Doppler log simulator, a deep sounding apparatus simulator and a combined navigation computer; wherein the gravimeter simulator comprises a gravity sensor, a chart of digital gravity anomaly, and a computer; the Doppler log simulator comprises a Doppler log and a computer; the deep sounding apparatus simulator comprises a deep sounding apparatus and a computer; the combined navigation computer is realized by an industrial computer, the synchronous control of the path generator, the inertia measuring unit, the gravimeter simulator, the Doppler log simulator and the deep sounding simulator is realized by a serial port, the transmission and receiving of information are performed on the inertia measuring unit, the gravimeter simulator, the Doppler log simulator and the deep sounding apparatus simulator, the combined navigation calculation and estimation analysis are performed, and the result is displayed through a terminal.

The invention discloses an underground-cavern-group-construction-schedule simulating optimization method based on ventilation numerical simulation. The underground-cavern-group-construction-schedule simulating optimization method includes the following steps that (1) ventilation numerical simulation and the underground-cavern-group construction schedule are combined, and an underground-cavern-group-construction-schedule simulating optimization mathematical model based on ventilation numerical simulation is established; (2) an underground-cavern-group-construction-ventilation two-phase-flow hybrid simulation theoretical method is provided; (3) an underground-cavern-group-construction-ventilation numerical simulation parameter base is established; (4) an underground-cavern-group-construction-ventilation three-dimensional fine physical model is established, and grids are divided; (5) underground-cavern-group-construction-ventilation two-phase-flow hybrid simulation under different excavation schedules is achieved; (6) simulating optimization analysis of underground-cavern-group-construction whole process is carried out in cooperation with the ventilation numerical simulation result. According to the underground-cavern-group-construction-schedule simulating optimization method based on ventilation numerical simulation, the whole wind flow structure, pollutant space distribution and the dynamic variation rule in cavern groups are solved, and wind-flow-field transient pulsation information and the dust particle dispersion mechanism of ventilation difficulty areas can also be obtained.

The invention discloses a method for evaluating resistance of sandy soil on an embedded submarine pipeline under the action of waves. The method comprises the steps that soil body samples with different relative densities are prepared by obtaining sandy soil samples; different initial static stress ratios are selected for soil body samples with the corresponding relative densities, different dynamic cyclic stress ratios are applied to the soil body samples, the frequency of dynamic cycle and loading time are controlled, and a dynamic stress-strain change rule curve and a cyclic strength change rule curve are obtained; according to the dynamic stress-strain change rule curve and the cyclic strength change rule curve, a sandy soil dynamic strength-deformation and pore water pressure growth mode theoretical model is established, horizontal force and vertical force are applied to the pipeline, the size of constraint force of a sandy seabed on the embedded submarine pipeline is further obtained according to a load-displacement relationship, and a basic theoretical method is provided for design of embedding the pipeline in the seabed and evaluation of stability.

The invention discloses a shallow rainfall-induced landslide early-warning method based on unsaturated soil mass water content, which belongs to the field of mountain disasters. The shallow rainfall-induced landslide early-warning method adopts an unsaturated soil mechanical theory, a hydrology theory and a landslide stability analysis theory, and combines real-time monitored landslide soil mass volumetric water content for solving a stability coefficient of landslide unsaturated soil in real time, establishes an early-warning index based on stability conditions specified by specifications, and achieves real-time early warning of shallow rainfall-induced landslide under an unsaturated condition. The shallow rainfall-induced landslide early-warning method is reliable in theoretical method, scientific and convenient in calculation, establishes the early-warning index based on specifications, solves the problem of applicability of shallow rainfall-induced landslide unsaturated damage mechanical mechanism in early warning, and improves reliability, accuracy and scientificity of forecast. The shallow rainfall-induced landslide early-warning method can provide technical support for stability analysis and monitoring early warning of shallow rainfall-induced landslide directly.

The invention discloses a machine-vision-based curve speed limitation calculating method and speeding warning device; the method comprises the steps of measuring a visual distance of a curve unequal-visual-distance poor section; according to the visual distance, calculating a safety speed that allows a vehicle to stop emergently in the case of emergencies; comparing the safety speed with a current speed, and giving a warning to a driver if the current speed is higher than the safety speed; the method is based on a vehicle device, has no need for assistance from road facilities, and has the advantages that the cost is low, calculation is speed, operating speed is high and the reliability is high, traffic accidents due to the fact that a driver assumes good road conditions ahead and gains an insufficient braking distance are prevented, and support is provided for speed safety control theoretical methods for poor sections.

The invention discloses a graph theoretical method MalZero for quickly and accurately detecting zero-day malicious software. The method is characterized in that features are extracted from API calling graphs to establish a classifier model, benign software and malicious software have different graph theoretical properties in respective API calling graphs, and the graph theoretical features extracted from the API calling graphs can be used for distinguishing the malicious software from the benign software effectively and efficiently. Three modules, namely a graph construction module, a feature extraction module and a graph classification module are involved in the method. Through the MalZero, the malicious software can be quickly and accurately detected on a terminal host, high efficiency is achieved in terms of storage space and detection time, and the MalZero can supplement an existing malicious software detection scheme of the terminal host due to low overhead.

The invention belongs to the technical field of robot data processing and discloses a two-wheeled robot motion control system and method based on complementary filtering. The method comprises the steps of carrying out data fusion on an attitude sensor MPU6050 on-chip gyroscope and an accelerometer through utilization a first-order complementary filtering method and obtaining an attitude dip angle;obtaining robot two-wheel speed through utilization of an incremental encoder, and moreover, obtaining track path information through utilization of a camera; and controlling a motor PWM control signal through adoption of a PID closed-loop control algorithm, and realizing dynamic balance control. Through adoption of a fusion technology of various control theoretical methods, robot adaptive balance capability is realized. Fuzzy plus proportion control technologies are employed for an automatic cruise system, so a robot can pass a curve rapidly and smoothly. Through adoption of wireless networktransmission technologies such as 4G and Wi-Fi, manual intervention capability of the robot is rapidly and conveniently improved. The robot can be operated in a complex environment.

The invention discloses a method for determining the fatigue crack safe damage growth period of an airplane structure. The method for determining the fatigue crack safe damage growth period of the airplane structure is characterized by comprising the steps of (1) determining a crack growth mid-value period, (2) determining the fatigue crack growth dispersion coefficient, (3) determining the structure safe damage growth period based on the frequency of overhauling. According to the method for determining the fatigue crack safe damage growth period of the airplane structure, a theoretical method is provided for prolonging the service life of the airplane structure and guaranteeing safe flight of an airplane. Compared with an existing method for determining the fatigue crack safe damage growth period of the airplane structure, the method used for determining the fatigue crack safe damage growth period of the airplane structure and based on the frequency of overhauling has the advantages that information of structure overhauling is considered when the safe damage growth period is determined.

The invention provides a method for calculating axial compressive stress of a novel quadrilateral chiral honeycomb. The method comprises the following steps: step 1, based on geometric configuration of the quadrilateral chiral cell-element honeycomb, calculating total energy absorbed by a telescopic unit; step 2, calculating total energy absorbed by four additional plane units; and step 3, based on the total energy absorbed by the telescopic unit and the total energy absorbed by the four additional plane units, which are calculated in the steps 1 and 2, calculating the axial compressive stress of the quadrilateral chiral cell-element honeycomb under axial compression according to an energy conservation principle. According to the method, a theoretical method for calculating the axial compression stress is given out in combination with a super folding unit theory based on the energy conservation principle, and the axial compression of the quadrilateral chiral cell-element honeycomb is simulated by applying a finite element simulation technology, so that the correctness of the theoretical calculation method is verified.