34 results about "Differential transformation" patented technology

The invention provides an LC-DSM algorithm (low-complexity differential detection algorithm). Firstly, a symbolic matrix is constructed at the transmitting end of a differential spatial modulation system by applying a bit filling scheme and a transmission bit calculation formula, and a receiving signal is obtained at the receiving end through differential transformation and transmitting. Then a search mode of detection by column is adopted on a receiving matrix based on the equation structure of a differential maximum likelihood detection algorithm to perform signal decision column by column so that a transmitting symbol and the sequence number of a transmitting antenna are obtained. Finally information bits are obtained through inverse mapping according to the corresponding relation of the bit and the transmitting symbol and the bit and the sequence number of the transmitting antenna. The method is obtained by combination of the low-complexity detection algorithm under spatial modulation and the equation structure formed by the maximum likelihood detection algorithm under the differential spatial modulation system. The research indicates that complexity is greatly reduced relative to the differential maximum likelihood detection algorithm by using the LC-DSM algorithm under the premise of guaranteeing no loss of algorithm performance.

The invention discloses a magnetic vortex array imaging detection method and a magnetic vortex array imaging detection device for detecting the defect of a steel plate, wherein the method comprises the following steps: acquiring a characteristic parameter and determining an optimal excitation frequency; exciting a sinusoidal alternating current magnetic field and inducing an alternating vortex current; acquiring an induction alternating magnetic signal near a detected area of the detected steel plate; processing the induction alternating magnetic signal and conducting the first differential transformation operation to obtain a transformed differential signal; judging whether the differential signal is less than the preset threshold, if so, judging that no defect exists, otherwise, judging that the defect exists, and extracting an area signal; inputting the area signal into a constructed neural network model to implement defect reverse inversion to obtain a defect profile parameter; and drawing a defect profile according to the defect profile parameter to realize imaging. The method uses a concentric ring type magnetic vortex array detection array to detect the defect, so that the defect of the steel plate is detected at the high accuracy, the detection accuracy is improved, and the defect imaging effect is improved.

The invention relates to a constant speed servo unit for controlling angle signals and a control method thereof. A steering vertical column is supported to a flange in a rotation manner, a lower gearbox is fixed to the lower portion of the steering vertical column, a large swiveling gear is mounted on the upper portion of the steering vertical column, a hydraulic steering motor is fixed onto the flange, an output shaft of the hydraulic steering motor is connected with an input shaft of a planetary reducer, a drive pinion is mounted on an output shaft of the planetary reducer, the drive pinion is meshed with the large swiveling gear, the large swiveling gear is further meshed with a reduction gear which is provided with a rotary encoder, the rotary encoder is in communication connection with a rubber angle display and a PLC (programmable logic controller) control unit respectively, the PLC control unit is in control connection with a potentiometer on an operation handle and a proportional valve respectively, and the proportional valve is located in an oil circuit of the hydraulic steering motor. Margin calculation is performed to a rubber angle instruction and rubber angle feedback, a rubber angle feedback signal is subjected to differential transformation of time to calculate steering speed, and the proportional valve is regulated according to difference between a steering speed instruction and actual steering speed.

The invention relates to a sequence overlapping differential direction protection method for a power transmission line with a static synchronous series compensator, and belongs to the technical field of relay protection of power systems. The method includes the steps that when a failure occurs in the power transmission line with the static synchronous series compensator, line mode voltage transient quantity ul and line mode current transient quantity il with fault phases are collected and calculated through a direction relay R1 at the measurement end M, four-order sequence overlapping differential transformation is conducted on ul and il, and then a voltage differential sequence Sul and a current differential sequence Sil are acquired; the power differential sequence SPl is acquired by multiplying the voltage differential sequence by the current differential sequence, and the direction of the failure is judged according to whether the polarity of a first nonzero mutation in the SPl is positive or negative; if the polarity is negative, the failure is judged as the forward failure, or else the failure is judged as the reverse failure. According to the method, the power differential sequence acquired by multiplying the voltage differential sequence by the current differential sequence, the direction of the failure is polarized, and judgment is reliable and effective.

The invention relates to a method for calculating the inherent frequency of a Euler-Bernoulli beam through an improved differential transformation method. The method comprises the steps that the improved differential transformation method is deduced on the basis of a differential transformation method; a corresponding oscillatory differential equation is built, the improved differential transformation method is used for solving the free vibration problem of the homogeneous Euler-Bernoulli beam with two freely-supported ends, a control differential equation is converted into an algebraic equation, and boundary conditions are changed to an algebraic frequency equation convenient to calculate; corresponding algebraic operation is carried out to obtain the inherent frequency and the modal shape of any order of the differential equation. According to the method for calculating the inherent frequency of the Euler-Bernoulli beam through the improved differential transformation method, the improved differential transformation method is used for solving the free vibration problem of the homogeneous Euler-Bernoulli beam, an approximate solution of a nonlinear problem is obtained in the mode that iteration is carried out to converge the series, closed-form solutions such as the four-order inherent frequency and the modal shape are obtained, the solution of a Taylor expansion power series can be converged at a larger time interval, and the calculation process is rapider and more accurate.

The invention provides a comparison type directional protection method for travelling wave polarity by utilizing crossing sequence differential transformation, and belongs to the field of power system relay protection. The directional protection method comprises the following steps: when a power transmission line breaks down, extracting signals of a failure voltage and a failure current by a protecting and measuring device; performing the crossing sequence differential transformation on the extracted travelling wave signals so as to obtain a transformation quantity of the crossing sequence differential transformation of the failure voltage and the failure current; distinguishing a positive direction failure and an opposite direction failure by utilizing a discriminant of the comparison type directional protection method for the travelling wave polarity. According to the invention, a faulted travelling wave is detected by utilizing an algorithm of the crossing sequence differential transformation, so that although an interference signal is amplified, the interference information is restrained to a certain extent as compared with the amplification effect of failure information.

The invention provides a cloud computing load prediction method based on a deep belief network. The cloud computing load prediction method comprises the following steps of (1) extracting and aggregating load observed values from a cloud group; (2) performing differential transformation on the observed values of the step (1), so as to reduce the linearity of data, normalizing the data, and analyzing autocorrelation and autoregression characteristics in the data; (3) training RBM (Restricted Boltzmann Machines) layer by layer from bottom to top, and optimizing a whole network structure through a BP (Back Propagation) algorithm; (4) performing short-term and long-term prediction on cloud attributes by using the network trained in the previous step; (5) performing inverse transformation opposite to the step (2) on prediction results in the step (4), so as to obtain predicted values of raw data. The cloud computing load prediction method has the advantages of small prediction error, being suitable for long-term prediction and the like, a reliable basis can be provided for resource scheduling of a cloud platform, and the effects of efficient scheduling and use of cloud resources are achieved.

The invention discloses an outpatient number prediction method and system based on an automatic deep belief network. The everyday outpatient number is collected from a hospital registration system to obtain historical outpatient number data, differential transformation pretreatment is carried out on the historical outpatient number data to obtain differential data, a deep belief network structure is automatically constructed in dependence on the differential data, groups are automatically created by means of a clustering algorithm to obtain grouped data in different time series, then the deep belief network is trained in dependence on the grouped data to obtain an outpatient number prediction model, finally the outpatient number prediction model is called to predict the outpatient number in a designated time series to obtain a prediction result, and inverse transformation of the pretreatment is carried out on the prediction result to obtain the predicted outpatient number. The deep belief network is advantaged by being convenient to use and simple to train, and can provide a reliable basis for the prediction of the hospital outpatient number, and is small in prediction error, and is especially suitable for long-term prediction.

The invention discloses an intelligent terminal for achieving multi-channel electrocardiogram QRS automatic planning. The intelligent terminal comprises a processor and a Bluetooth communication module connected with the processor. The processor comprises a signal receiving module, a wavelet transformation module, a differential transformation module, a kurtosis and weight calculation module, a signal superposition and filter module and an R peak detection module. The intelligent terminal solves the problem of R peak detection errors caused by desynchronization of certain channel signal planning through multi-channel electrocardiosignal fitting; meanwhile, the kurtosis value of signals is taken as reference in the signal fitting process, and the problem that the quality of an integral comprehensive energy curve is decreased due to the fact that the quality of signal waves of a certain channel is too poor is solved. Thus, the electrocardio R peak detected by the intelligent terminal is stable and accurate in effect, and especially the position of the R peak can be accurately detected even when the quality of the signals of part of channels in the electrocardio signals does not meet the standard.

The invention discloses a fast and real-time video coding and decoding compression algorithm. The coding algorithm comprises the following steps of S01, inputting a bitmap image sequence, and performing the brightness color difference signal transformation on the bitmap image sequence; S02, performing the differential transformation on the bitmap image sequence after the brightness color difference signal transformation process; S03, performing the fast frequency domain transformation on the bitmap image sequence after the differential transformation process; S04, performing the rapid quantization on the bitmap image sequence after the fast frequency domain transformation process; S05, conducting the entropy compression on the fast quantized bitmap image sequence, and outputting the coded data of a compressed video. In addition, the invention discloses the specific steps of the decoding algorithm. According to the invention, the information of a high-definition image can be compressed at about 8-16 megabytes per second based on software. In this way, the transmission and storage problem during the video real-time coding and decoding process of a video processing host and partly embedded equipment without special hardware processing in the prior art is solved. The method can be widely applied to the fields of remote control, remote monitoring and the like for computer equipment.

The invention relates to a power distribution network disaster prevention backbone network frame planning method based on a Steiner tree model. The method comprises the following steps: firstly, on the basis of meeting the power supply of important users of a power distribution network under typical disaster conditions, establishing a Steiner tree model of a disaster prevention backbone network frame of the power distribution network based on network connectivity constraint and power flow constraint by taking the minimum construction cost and disaster risk of a line and a tower as an optimization target; and solving the optimization model by using a binary particle swarm algorithm to obtain an optimal backbone network frame scheme, and realizing power supply of the power grid to importantusers in disasters. According to the method, the comprehensive cost of carrying out differential transformation on the backbone network frame is considered, power supply of the power grid to importantloads during disasters is guaranteed, and the power supply self-guarantee capability of the power grid under the disasters is improved.

The invention relates to an automatic battery parameter identification method, which comprises the following steps of: establishing a second-order RC equivalent circuit model, and carrying out discrete and differential transformation to obtain an electrical expression of the circuit model; carrying out Laplace transformation on the electrical expression of the circuit model, converting the electrical expression into a z transformation form, carrying out linear transformation, and converting the electrical expression into a time domain discrete equation; converting the time domain discrete equation into a vector form based on a time domain discrete equation; establishing a recursive least square method with a forgetting factor lambda, and performing recursive iteration based on the recursive least square method to calculate a to-be-identified vector; after the recursion frequency d is set to reach the recursion frequency d, obtaining a set of model parameters through a recursion least square method, calculating the SOC of the battery through the model parameters in combination with extended Kalman filtering, and because of a certain linear relation between the SOC and the open-circuit voltage OCV, obtaining the open-circuit voltage OCV through the calculated SOC; and calculating an absolute value of a difference value (delta OVC) between the open-circuit voltage OCV and the open-circuit voltage, and if the absolute value of the difference value (delta OVC) exceeds a set range, performing parameter suppression.

The invention discloses a household load prediction method and system based on load characteristics and a power consumption behavior mode. The method comprises the steps: firstly collecting a household original power consumption load time sequence to obtain an original data set, and carrying out the preprocessing of the original data set to obtain a complete original data set; then collecting power utilization data characteristics from the complete original data set by adopting a PCA algorithm based on load characteristics and a power utilization behavior mode, completing characteristic extraction based on an SVD decomposition covariance matrix, realizing data dimension reduction, obtaining a stable sequence through differential transformation and Exponential motion averge processing, capturing a more complex nonlinear relationship of the sequence by utilizing a combined model, and obtaining a power utilization characteristic matrix. A data input structure is optimized, so that the model is combined with a historical state during prediction, the fitting precision is improved through a multivariable model, and the precision of an existing power load prediction method is improved.

The invention relates to a transient-state quantity polarity comparison type bus protection method on the basis of sequence overlapping and differential transformation, and belongs to the field of relay protection technologies for electric power systems. The transient-state quantity polarity comparison type bus protection method includes extracting voltage and current signals of various lines connected with bus when faults of the lines or the bus occur and computing line-mode voltages and line-mode currents by the aid of three-phase voltages and currents; carrying out sequence overlapping and differential transformation on the line-mode voltages and the line-mode currents of the various lines, solving differential transformation voltages and differential transformation currents, carrying out sign function transformation on product results of the differential transformation voltages and the differential transformation currents to obtain sgn(SP<k>), adding the sgn(SP<k>) of all the lines connected with the bus, acquiring absolute values to obtain values and determining that the faults of the lines occur if the values are smaller than the quantities of current transformers; determining that the faults of the bus occur if the values are equal to the quantities of the current transformers. The line-mode voltages and the line-mode currents comprise fault phases.

Provision of a new communication device that uses pneumatronic waves as transmission medium, taking advantage of the characteristics of responsive materials such as ceramics. The space communication device contains a transmission means that generates pneumatronic waves vibration-modulated by letting electromagnetic waves carrying information signals act on wave-transferred inorganic materials, a receiving means that detects as information signals electromagnetic waves generated by the coming pneumatronic waves, which act on the said wave-transferred inorganic materials to vibration-demodulate such materials, and a differential transformation means that prevents the said electromagnetic waves from impeding receiving action.

The invention relates to the field of comprehensive energy system calculation and analysis, in particular to an electric heating comprehensive energy system dynamic energy flow calculation method based on differential transformation, which comprises the following steps: S1, defining differential transformation under a per unit value system; s2, applying the defined differential transformation to a nonlinear-partial differential-algebraic equation model of the dynamic energy flow of the electric heating integrated energy system, and converting the nonlinear-partial differential-algebraic equation model into a group of explicit linear recursive relational expressions; s3, by solving the relational expression, obtaining an expression of each state quantity about time, and further obtaining a change track of each variable of the model along with time; and S4, an adaptive time window strategy based on local truncation error estimation is used to accelerate the energy flow calculation process, the convergence of the calculation is ensured, and the efficiency and robustness of the energy flow calculation are improved. According to the method, efficient and robust calculation of the dynamic energy flow can be realized.

The invention discloses a metal plate strain measurement method based on Fourier differential transformation. The method comprises the steps of smearing a measured metal plate with uniform speckles, taking the speckles as mark points during signal collection, carrying out a tensile experiment on the measured metal plate, and collecting the image signals of the mark points during the stretching of the metal plate; converting the image signal of the mark point into a displacement signal, and simultaneously performing spline interpolation for three times along the x and y directions to obtain an interpolation signal; extending the interpolation signal along the x and y directions at the same time to obtain an extended signal of the mark point; carrying out discrete Fourier transformation on the continuation signal in the x direction and the y direction to obtain a displacement signal in a wave number domain; respectively carrying out differential transformation on the displacement signals in the wave number domain to obtain a dependent variable of the continuation signal in the wave number domain; and carrying out inverse Fourier transform on the dependent variable of the continuation signal in the wave number domain to obtain real strain values of the metal plate in the x and y directions.

The invention discloses a direct-current fan failure alarm circuit. The direct-current fan failure alarm circuit comprises a power supply, a direct-current fan, a sample resistor, a differential transformation circuit, an integral transformation circuit, a driving circuit and a dry contact alarm output circuit. The power supply is connected with the direct-current fan and the sample resistor in series, the signal receiving end of the differential transformation circuit is connected between the direct-current fan and the sampling resistor, the differential transformation circuit filters direct-current components after receiving pulse voltage signals output by the sampling resistor to obtain periodic alternating signals which are the same as rotating speed of the direct-current fan, and transmits the periodic alternating signals to the integral transformation circuit, after the integral transformation circuit conducts integral processing on the received periodic alternating signals, the periodic alternating signals are transmitted to the driving circuit to be amplified and then output to the dry contact alarm output circuit, and alarm output is controlled through control of switching-on and switching-off of an electromagnetic relay coil in the dry contact alarm output circuit.