122 results about "Random response" patented technology

Methods and apparatus to optimize delivery of multicast content using probabilistic feedback. A method is provided for transmitting data from a server to a plurality of receiving terminals. The method includes transmitting the data from the server to the plurality of receiving terminals, and generating a random response value at each receiving terminal. The method also includes comparing the response value to an acknowledgement value at each receiving terminal, and transmitting an acknowledgment signal to the server from selected receiving terminals. The selected receiving terminals are a portion of the plurality of receiving terminals where the response value has a selected relationship to the acknowledgement value.

The invention discloses an individual differential privacy protection method for high-dimensional data publishing in a distributed environment. According to the method, the correlation among properties is quantified through mutual information, and the mutual information of corresponding property pairs is calculated by use of a mutual information formula; an approximate k-degree Bayesian network isconstructed according to the mutual information, and the Bayesian network can well reflect dependency among the properties; privacy budgets are allocated individually according to the quantity of sensitive properties and the quantity of non-sensitive properties meeting conditions; all participants perform noise addition processing on data according to the allocated privacy budgets, and a random response mechanism is adopted to perform noise addition; and the data obtained after noise addition is sent to a manager, the manager gathers the data and synthesizes the data into an integrated dataset, and then the dataset is published to the outside. Through the method, when the data is published, a privacy requirement is guaranteed, a large amount of processing data is reduced, therefore, change of the data is lowered, the utility of the data is improved, and the method is beneficial for a data analyzer to perform relevant analysis.

The invention discloses a physical unclonable function based on reconfigurable ring oscillators and a generation method of the physical unclonable function based on the reconfigurable ring oscillators. The physical unclonable function comprises a reconfigurable ring oscillator matrix, a mapping module and a control module. The reconfigurable ring oscillator matrix is formed by reconfigurable bit generators, wherein the number of the bit generators in the matrix is determined according to the requirement in practical application. Each reconfigurable bit generator is formed by a reconfigurable oscillation loop, a counter, a register and a comparator. The reconfigurable ring oscillator matrix can extract random differences introduced between gate circuits in the manufacturing and machining processes and can generate random response signals. The mapping module has the function of generating a pair of configuration signals corresponding to each excitation signal for each excitation signal. The control module controls and coordinates work of the mapping module and work of the configurable ring oscillator matrix. Compared with a physical unclonable function based on the traditional ring oscillators, hardware implementation cost is greatly reduced, and the physical unclonable function has wider application prospects in safety fields such as the encryption authentication field.

The invention relates to a damage identification method based on improved similar Bayesian calculation. According to the damage identification method, a likelihood function of a parameter is not required to be calculated on solving of parameter posterior probability distribution by using similar Bayesian calculation, and the problem that the likelihood function cannot be solved in actual engineering application is solved; when Markov Chain Monte Carlo sampling is carried out, a probability model which is similar to a solved problem is established, then random sampling on the model is carried out, and a statistical characteristic estimated value can be obtained by using the sample and serves as an approximate solution of the original problem. Required calculated quantity on a complex engineering problem is quite high by using a Markov Chain Monte Carlo sampling method; by the damage identification method, a statistical characteristic value which is responded by a structure corresponding to a parameter sample is quickly calculated by a random response surface in a sampling process, a phenomenon that numerical solution is carried out by a finite element model is avoided, so that the calculation efficiency is greatly improved, and the problem that a Bayesian method cannot be implemented under the conditions of multiple parameters and large sample amount due to over large calculated quantity is solved.

A low frequency oscillation on-line analysis and early warning method of an electric power system includes the steps of acquiring and preprocessing a frequency signal, estimating frequency and a damping ratio of an oscillation mode, determining a dominant mode, and performing early warning of a dominant modal state. The method is based on self-adaption detrend processing of empirical mode decomposition, steady state and nonlinear components of system response under stimulating of disturbance in different strengths can be eliminated, and dynamic oscillation characteristics of the system response can be kept; an expanding stage Yule-Walker method is combined to estimate the system oscillation mode, energy of the oscillation mode is calculated, and the dominant mode of the system is determined; according to the strength of damping, safety, alert or emergency information of system oscillation is sent. The method can be applied to distribution network frequency signals, practical value is high, an estimated result is accurate, free response to the system and random response to the system can be performed uniformly, the method is applicable to on-line analysis of low frequency oscillation modes of a large-scale electric power system, and the method provides oscillation early warning information to a control center timely.

The invention discloses a reliability robust design method for a multi-failure mode of a superdeep well lifting container. The method includes the following steps of (1) determining structural parameters, material properties and dynamic load randomness of the lifting container, and adopting an experiment design method for figuring out a random response to a structure failure under random parameters; (2) according to a failure criterion of the lifting container, creating a reliability performance function under each failure mode; (3) taking the probability correlation among the failure modes into account, and adopting a copula theory for creating a combined probability model of correlative failures; (4) creating a system reliability model correlative with failures of the lifting container under the combination of the combined probability model; (5) creating a sensitivity model of the system reliability of the lifting container for each random parameter; (6) under the combination of an optimization design model, creating a lifting container reliability robust optimization design model with the combined failure probability and parameter sensitivity as constrains.

The invention provides a bridge impact coefficient optimization method based on the parameter identification technology, solving the problems in the calculation of impact coefficient and the optimization of impact coefficient sensitivity in stochastic dynamics, which can reduce the damage of bridge. The method is carried out in this manner: (1) defining a vehicle model, (2) deriving the equation of motion MU<..>+CU<.>+KU=F<g>+F<w>, according to the D'Alembert's principle; using the PIM method to solve deterministic response and using the PEM to calculate random response, U(t)=integral H(t-[tau], t)(F<g>([tau])+F<w>([tau])) differential [tau], t belongs to (0, t). The invention provides an effective optimization method for non-stationary random vibration of a vehicle-bridge coupling system, and improves comfort and safety of the vehicle and the bridge. The method of the invention has both accuracy and efficiency, and can provide better technical support for vehicle-bridge coupling vibration sensitivity analysis and optimization. The computational time required by the PEM-PIM numerical method is more than ten times that of the Newmark method when the computational accuracy is the same, and the method of optimizing the sensitivity of the self-identification design variables is proposed.

The invention discloses a random response surface method-based probabilistic optimal power flow calculation method. The method comprises the following steps of: first, expressing input random variables by a function relationship of a group of standard normal distribution variables by utilizing an equal probability transformation theory, so as to construct a second-order chaos polynomial corresponding to output variables; selecting appropriate configuration points of the normal distribution variables by using an optimal point selection method according to the number of undetermined coefficients in the chaos polynomial; converting the configuration point into sample point values of the input variables; for the random variables which have correlation, carrying out processing by applying an Nataf transformation theory so as to obtain a corresponding sample point; and finally, using the sample point as a disturbance variable to substitute to a power flow equation, carrying out deterministic optimal power flow calculation by using a prime-dual interior point method so as to obtain a system of linear equations about polynomial coefficients, solving the system of linear equations to obtain polynomial coefficients, obtaining numerical characteristics of the variable according to the obtained chaos polynomial of the variable, and estimating a probability density function and a probability distribution function of the variable by applying a kernel density estimation method.

The invention relates to a random response surface method and interior point method based wind-power-plant-contained random optimal power flow solving method, and belongs to the day-ahead dispatching plan researching field of a power system. The solving method comprises the following steps of obtaining system related data of a next dispatching cycle; taking a minimum power-generation and electricity-purchasing cost within a given time frame (24-hour time frame) as the target, and establishing a wind-power-plant-contained classical dynamic optimal power flow model; solving active output of the wind turbine in each single time frame by adopting the random response surface method; taking the air speed as the input variable and performing standardizing, and taking the active output as the output response to obtain an active output probability distribution function of the wind turbine; substituting the random air speed to solve the active output expectation of the wind turbine generator within a 24-hour time frame; and then substituting the optimal power flow model, and solving the optimal solution by adopting the interior point method. According to the solving method, the random response surface method and the interior point method are combined to solve the wind-power-plant-contained dynamic optimal power flow; and the problem of more calculation times, long simulation time and large occupied internal storage of the conventional randomness analysis method is comprehensively solved.

The invention discloses a method for identifying a low frequency oscillation parameter of a power system from random response data and belongs to the technical field of analysis of the power system. The method comprises the following steps of: monitoring an active power amplitude of each element in the power system in real time, selecting active power sampled data of each element in a sampling time window by two criteria and removing the sampled data which does not meet the criterion conditions; carrying out band-pass filtering processing on the sampled data obtained by selection; then obtaining an autocorrelation function and a cross-correlation function; and identifying oscillation frequency and damping ratio parameters of a low frequency oscillation mode of the system and carrying out online monitoring and early warning of low frequency oscillation on the basis of the identified parameters. According the invention, real-time monitoring on the frequency and the damping ratio of the low frequency oscillation mode of the power system can be achieved and early warning is carried out under the necessary condition; reference can be provided for power grid operating personnel to carry out related operation; and safety and stability of the system are improved.

The invention concerns a method (300) and system (110) for electronically generating random responses in a portable electronic device (110). The method includes the steps of detecting (316) motion of the portable electronic device, in response to the detecting step, generating (318) the random response and outputting (320) the random response to a user of the portable electronic device. The method can further include the steps of prompting (312) the user to ask a question and following a predetermined time period after prompting the user to ask the question, prompting (314) the user to shake the portable electronic device. The prompted question can be answerable with a yes or no.

The invention relates to a method for detecting high-speed train passenger comfort degree. The method comprises the following steps: A. virtual track irregularity used for elastic train body random power analysis is generated by adopting a virtual excitation mode; B. an elastic train body random vibration frequency domain is analyzed and an elastic train body random response is obtained; and C. passenger comfort degree of an elastic train body is calculated and assessed by utilizing different irregularity standards according the obtained random response. An elastic train body large-scale definite meta-model is adopted to assess comfort degree of passengers on different positions of the elastic train body. The virtual excitation mode and a symplectic algebra theory are adopted in the assessment process so that strong support is provided for enhancing high-speed train body structure design capacity, and a high-efficiency and reliable theoretical and numerical simulation technology is laid for researches of further optimizing and controlling the train and track structures.

The invention discloses a method for analyzing a random response of a non-proportional damping structure under an earthquake effect. The method comprises the following specific steps: 1, acquiring a unit impulse response of the structure about any excitation; 2, based on a random vibration theory, establishing a direct convolution formula responding to power spectrum calculation; 3, performing PODfeature orthogonal decomposition on the non-uniform modulation function excited by each point; and 4, calculating an evolution frequency response matrix by using FFT, and further determining an evolution power spectrum matrix and a variance matrix of the structure response. According to the method, the response statistics is explicitly represented as the convolution form about the pulse response,and the convolution is calculated by using the FFT technology, so that the response calculation efficiency is greatly improved; the method is suitable for a linear structure, is also suitable for a nonlinear structure, and can also be used for a linear system subjected to order reduction through a modal superposition method.

The invention discloses a structural topological optimization design method taking a random displacement response variance as a target, which is used for solving the technical problem of low practicality of an existing structural topological optimization design method. According to the technical scheme, multi-point acceleration is converted into force to be applied to a structure by adopting a large mass method; random response analysis is converted into simple harmonic response analysis by adopting a virtual excitation method; and a displacement response is calculated by using a mode superposition method. Then design is performed by taking a minimum variance value of a power spectrum of the displacement response in a concerned position of the structure as a target and taking a volume fraction of the structure as a constraint in a considered frequency band. Compared with a design method of a background technology, the method considers that the stability of a frequency response curve is intuitively measured by the random displacement response variance and the topological optimization design is performed by taking the random displacement response variance as the target. Finally a clear and effective structure configuration can be obtained by design, so that the design demand of making a random displacement response curve of the structure stable as far as possible in practical engineering can be met. Therefore, the method has extremely high practical engineering application values.

The invention discloses a random optimal trend calculation method based on a random response surface method. The influences of randomness of input variables are taken into consideration in an optimization process, and finally, a group of optimal solutions satisfying certain opportunity constraints are obtained. The method comprises the following steps: first of all, power system information is input, random input variables (disturbance variables) in a system are determined, the input variables are substituted as expected values, and an optimal scheduling scheme is obtained by performing deterministic optimal trend calculation by use of a primal-dual interior-point method; then, a probability trend is calculated by use of the random response surface method, a probability distribution of system state variables under the scheduling scheme is obtained, and random variables with correlation are processed by use of Nataf transformation; and finally, by use of a probability distribution function, whether the state variables satisfy restrictions of the opportunity constraints is determined, if not, upper and lower limits of the opportunity constraints are adjusted, and the steps of the deterministic optimal trend calculation and opportunity constraint examination are restarted until a scheduling scheme satisfying the opportunity constraints is obtained.

The invention provides a method for calculating a risk indicator weight in long-span bridge risk assessment through the failure probability. The method is characterized by comprising the following steps of 1, building a long-span bridge structure random finite element model; 2, adopting a multinomial expansion based response surface collocation point obtaining method for considering a random variable in the step 1, calculating random response of the long-span bridge structure risk indicator under the most disadvantage effect combination, creating a limit state equation corresponding to the structure failure mode, and adopting a Monte Carlo method for simulating the limit state equation to obtain the failure probability of each structure risk indicator; 3, according to the failure probability of each structure risk indicator obtained through calculation in the step 2, and calculating the corresponding weight. The risk indicator weight is calculated by adopting the failure probability ofthe main failure state of the long-span bridge structure, the structure risk indicator weight is calculated in a quantitative mode, and the long-span bridge risk assessment conclusion objectivity isgreatly improved.

The invention discloses a high-precision acceleration DAC (digital-to-analogue conversion) digital filter applicable to strapdown inertial navigation and relates to the field of data acquisition. The filter comprises a sampling comb filter, an FIR double-extraction compensation filter and an FIR quadruple-extraction compensation filter, wherein the sampling comb filter adopts an efficient down-sampling filter structure put forward by Hogenauer and is used for realizing high-rate underclocking; the FIR double-extraction compensation filter is generated through a fir2 function in the matlab, the function can design a multi-band random response curve phase FIR filter, the filter is mainly used for compensating the pre-stage CIC (cascaded integrator comb) filter with attenuation on band margins and realizing double extraction; the FIR quadruple-extraction compensation filter calculates coefficients of the optimal filter with the Parks-McClellan algorithm, and the filter is low in pass band ripple, narrow in transition band, large in stop band attenuation and high in filter order. The high-precision digital filter meets the strapdown inertial navigation system data sampling requirement.

The invention aims to provide a dynamic analysis method of an air compressor frame. The dynamic analysis method includes the steps: structuring a finite element module of the air compressor frame; subjecting the finite element module to harmonic response analysis, modal response analysis and random response analysis respectively; using a displacement-frequent curve acquired from the harmonic response analysis, a PSD (phase-sensitive detector) acceleration response curve acquired from the random response analysis and low frequency acquired from the modal response analysis for contractive analysis and judging whether an air compressor frame structure is satisfactory to quality requirements or not. The dynamic analysis method has the advantages that the defects that an existing air compressor frame needs to be committed through loads of tests on structural design, is high in development cost and long in cycle length are overcome; the dynamic analysis method is simple in step, short in time consumption and highly reliable, and a theoretical foundation is provided for optimal design of the air compressor frame.

The invention relates to a method for resisting the attack of the security protocol refusing service in the wireless transmission layer, which belongs to intelligent information processing technology field. The invention is based on wireless transmission layer security protocol, combined with timer, access control, and server random number response and client terminal riddle mechanism, which resist three kinds of service-refusing attacks effectively, at first, it adds a handshake timer, data timer, for the wireless transmission layer security protocol, it resists the handshake quitting attack through the handshake timer, then uses access control mechanism, it resists the quitting security connection attacks through combining the data timer and the access control mechanism, finally, the server random response mechanism and the client terminal riddle mechanism are used to resist the exponential attack. The invention resists the three kinds of attacks, simple, easy, the security is upgraded greatly.

The invention provides a coupling uncertainty acquisition method for a high-altitude electromagnetic pulse field line based on polynomial chaos expansion. The method comprises the following steps that(1) a coupling model of a field line of a transmission line under a high-altitude electromagnetic pulse is established, and related input parameters are determined; (2) according to uncertainty variables set by a user and a submissive statistic characteristic distribution type of the uncertainty variables, unified conversion is conducted according to demands, corresponding polynomial bases are used, and a coupling random response is subjected to polynomial chaos expansion; (3) according to types of different polynomials, coefficients of all the polynomials are obtained through corresponding-form Gaussian integral, and an analytic expression of a coupling response of the high-altitude electromagnetic pulse field line is obtained; (4) according to the coefficients of all the polynomials anddistribution types of the uncertainty variables, statistic characteristic parameters of the coupling response of the high-altitude electromagnetic pulse field line are obtained, a fluctuation range,a probability density distribution function and a cumulative probability distribution function are obtained by using a Monte-Carlo method.

The invention discloses a double-crane system variable amplitude angle response modeling algorithm and a random response domain prediction method. The variable amplitude angle response modeling algorithm includes the steps: 1 building a system geometric model and giving coordinates of points; 2 building a system constraint equation; 3 building a variable amplitude angle response model according to the system constraint equation. The random response domain prediction method includes the steps: 1 describing uncertainty of a load according to a random parameter model; 2 building a random variable amplitude angle response equivalent equation based on the variable amplitude angle response model and the random parameter model; 3 proposing a perturbation random composite function method according to composite function characteristics and a random perturbation method, and solving random variable amplitude angle response expression; 4 further solving variable amplitude angle response expectation and variance. The prediction problem of a lower variable amplitude angle response domain with random parameters can be solved, the algorithm and the method have the advantages of high speed and precision, and system operation reliability is ensured.

The invention discloses an encryption system and an implementation method thereof, and the system comprises a true random number generator module which is used for generating a configuration signal, an excitation signal and a random plaintext; a response generation module which is used for generating a response value according to the excitation signal and the configuration signal, and the responsemodule has reconfigurability; a key generation module which is used for generating a key according to the response value; an ECC encryption and decryption module which is used for encrypting the secret key; and an SM4 encryption and decryption module which is used for encrypting the to-be-encrypted data according to the key to obtain a ciphertext. According to the system, the random response value is generated through the response generation module, so that the random key generated according to the random response value has unpredictability, and the random key is encrypted through the ECC encryption and decryption module, so that the security of the encrypted random key in the transmission process is ensured. The system can be widely applied to the technical field of encryption.

A data selection method in a federated learning scene comprises the steps of filtering out users and data related to tasks, user selection before training, user and data selection in the training process and model training. According to the invention, a vector sketch and a random response mechanism are adopted, a user selection strategy is efficient, and privacy protection is achieved; meanwhile,the server side log information is adopted to dynamically select the user; data is selected based on the gradient upper bound value, and the influence of error data on the gradient is considered, so that the data selection strategy is efficient and accurate.