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234 results about "Bayesian estimator" patented technology

Multi-source information fusion method based on factor graph

The invention relates to a multi-source information fusion method based on a factor graph. The multi-source information fusion method aims to realize full-source positioning and navigation without relying on satellite navigation in a complex environment, takes an inertial navigation system as the core, utilizes all available navigation information sources, and performs rapid fusion, optimal configuration and self-adaptive switching on asynchronous heterogeneous sensor information. A factor graph model is constructed by means of recursive Bayesian estimation, the factor graph is broadened by means of a variable node and a factor node of the system after measurement information of different sensors are acquired, state recursion and updating are completed based on a set cost function, and thefactor graph optimization problem is solved through sparse QR decomposition by adopting an increment smoothing method. The multi-source information fusion method effectively solves the time-varying state space problem generated between carrier motion and measurement availability, can calculate a solution of precise navigation according to dynamic changes of a carrying platform, realizes plug-and-play of multiple sensors, and meets the requirements of carriers changing in complex environment and different tasks.
Owner:SOUTHEAST UNIV

Scheduling rule intelligent excavating method based on rule parameter global coordination optimization

The invention relates to a scheduling rule intelligent excavating method based on rule parameter global coordination optimization, belonging to the automatic control, information technology and advanced manufacturing field, in particular relates to a complex production process oriented scheduling rule intelligent excavating method for scheduling environment in real time. The invention is characterized in that the method includes the following steps: a complex production process oriented scheduling rule intelligent excavating frame for scheduling environment in real time is built, a scheduling problem instance classification model is build, and scheduling rule parameter global coordination optimization problem is constructed and solved. The invention is based on the scheduling rule intelligent excavating frame provided by the invention and adopts double-layer fuzzy C-means clustering method to classify scheduling problem instances. Rule parameter global coordination optimization problem is constructed directing at scheduling problem instance in each class and linear partition based particle swarm optimization is adopted to solve and optimize the problem, wherein Bayes estimation method is adopted to carry out comprehensive evaluation on scheduling rule performance. The obtained scheduling rule has better scheduling effect on different problem instances in similar scheduling environment.
Owner:TSINGHUA UNIV

Progressive type three-dimensional matching algorithm based on sectional matching and bayes estimation

InactiveCN103383776AReduce the occurrence of mismatchesImage analysisStereo matchingMaximum a posteriori estimation
The invention discloses a progressive type three-dimensional matching algorithm based on sectional matching and bayes estimation. The progressive type three-dimensional matching algorithm includes: 1) dividing an image into an edge area and a sectional area on the basis of responding of a Sobel filter, matching through a three-dimensional matching strategy based on a window and a sectional matching strategy, and combining to obtain a pre-matching depth image; 2) for invalid points in the pre-matching depth image, fitting a least square plane through effective points in a support window, estimating the depth of the invalid point position, and thickening the pre-matching image; 3) for the obtained pre-matching image, revising the depth of each point through a bayes maximum posterior probability method, considering using pre-matching values as the prior probability, and considering using smoothness of similarity and depth of the image as the posterior probability. By means of the progressive type three-dimensional matching algorithm, extraction of depth images from thick to dense and from coarse to fine can be finished through a progressive structure, and meanwhile, edge characteristics and smoothness are considered, so that the accurate and smooth depth images can be obtained.
Owner:ZHEJIANG UNIV

Improved spectrum subtraction method based on human ear masking effect and Bayesian estimation

InactiveCN108735225AQuick response to changesOvercoming the defect of inaccurate noise estimationSpeech analysisNoise power spectrumNoise estimation
The invention discloses an improved spectrum subtraction method based on a human ear masking effect and Bayesian estimation. The improved spectrum subtraction method comprises the steps of: (1) adopting an improved minimum control value recursive averaging algorithm to obtain noise power spectrum estimation of an original noisy speech; (2) combining the obtained noise power spectrum estimation forperforming preliminary spectrum subtraction on a noisy speech signal; (3) performing Bayesian estimation based on weighted likelihood ratio distortion measurement on the signal after preliminary spectrum subtraction, and calculating the optimal estimated amplitude spectrum of the signal; (4) calculating a subtraction parameter of secondary spectrum subtraction by utilizing the human ear masking effect; (5) performing IMCRA noise estimation again before secondary spectrum subtraction, and carrying out secondary spectrum subtraction to obtain a final enhanced speech signal; (6) and performing inverse Fourier transform on the enhanced speech signal to obtain a final enhanced speech. The improved spectrum subtraction method better guarantees the intelligibility of the speech while improving the noise elimination capability of the algorithm, thereby improving the overall effect of speech enhancement.
Owner:NANJING UNIV OF POSTS & TELECOMM

Thin-walled part milling system with real-time deformation compensation function

The invention discloses a thin-walled part milling system with a real-time deformation compensation function. The thin-walled part milling system with the real-time deformation compensation function comprises a machine tool, a rigid chassis, a stand column, a fixing support, a laser displacement sensor, a displacement compensation controller, a power amplifier and a computer. A sheet to be machined is fixed to the rigid chassis through the stand column and installed on a machining groove of the machine tool, deformation and displacement of the sheet are detected through the laser displacement sensor, the machining path is predicted by the displacement compensation controller through a Bayes estimation algorithm, a cutting depth compensating signal is obtained, and a control command is output to control feeding of a spindle of the machine tool. By means of the thin-walled part milling system with the real-time deformation compensation function, deformation of thin-walled parts in the milling process can be detected in real time, deformation of the thin-walled parts in the subsequent machining path is predicted, Z-direction deformation during milling of the sheet is compensated through real-time control over the Z axis of the machine tool, the effect of the same milling depth of the thin-walled parts on the machining path is ensured, and accordingly the surface quality and precision for milling of the thin-walled parts are greatly improved.
Owner:HUAZHONG UNIV OF SCI & TECH

Apparatus and method for an overload control procedure against denial of service attack

The present invention is a methodology to prioritize packets based on the conditional probability that given the values of attributes carried by packet, the packet is a legitimate one. We will call this the conditional legitimate probability of a packet from here onward. The conditional probability of each packet is evaluated based on Bayesian estimation technique. This is accomplished by comparing the attributes carried by an incoming packet against the “nominal” distribution of attributes of legitimate packet stream. Since an exact prioritization of packets based on their conditional legitimate probability would require offline, multiple-pass operations, e.g. sorting, we take the following alternative approach to realize an online, one-pass selectively dropping scheme. In particular, we maintain the cumulative distribution function (CDF) of the conditional legitimate probability of all incoming packets and apply a threshold-based selective dropping mechanism according to the conditional probability value computed for each incoming packet. To speed-up the computation of the conditional legitimate probability for each incoming packet, we may, as an alternative, use the logarithmic version of the equation to implement the Bayesian estimation process. Other features of the invention include: providing means to guarantee minimum throughput of particular (pre-configured) type(s) of packets; providing a. Filtering Mechanism to suppress the noise during estimation/maintenance of nominal attributes distribution; applying state-of-the-art efficient algorithm/data-structures for quantile and histogram building/updates; using the proven, industrial-strength load-shedding algorithms as a submodule in the overload control algorithm; and being amenable to practical implementation to support online, one-pass processing on high-speed communication links.
Owner:LUCENT TECH INC

Cloud and rain microphysical parameter inversion method based on space-borne three-frequency millimeter wave radar

The invention discloses a cloud and rain microphysical parameter inversion method based on a space-borne three-frequency millimeter wave radar. The method comprises the following steps of firstly, calculating and analyzing cloud and rain particle temporal and spatial distribution characteristics and summarizing, using a generalized Gamma distribution function to characterize cloud raindrop particle distribution and carrying out parameterization; then, based on an idea of a Bayesian estimation theory, establishing an inversion model, presetting prior distribution of the parameters, inputting space-borne W, Ka and Ku three-frequency millimeter wave radar reflectivity factors into a physical model, inputting space-time matching ground-based millimeter-wave radar data as an adjustment factor,carrying out posterior, after iterative calculation, continuously correcting prior probability distribution to minimize the cost function and outputting an optimal inversion result; and finally, carrying out linear processing on an inversion result in each distance library to obtain the inversion result of an entire profile. In the invention, a space-time resolution is high, cost is low, the inversion result is fine and actual distribution of cloud and rain particles can be simultaneously inverted.
Owner:NAT UNIV OF DEFENSE TECH

Visible light channel estimation method and system

ActiveCN105471777AAccurate estimateComplete and accurate channel estimation parametersClose-range type systemsChannel estimationTime delaysCovariance
The invention provides a visible light channel estimation method and system. The method comprises the following steps: performing least square estimation on a channel transfer function corresponding to a pilot signal, and performing maximum likelihood estimation on time domain channel impulse response of a spatial position which receives the pilot signal so as to acquire the maximum likelihood estimation of the time domain channel impulse response at different positions in the visible light channel, computing a covariance coefficient of each tapping in the visible light channel under same moment and different time delays, self-adaptively selecting an optimal variable statistic window length, and then computing a time domain estimation value of each tapping as a mean value required by Bayes estimation, and acquiring the time domain Bayes estimation of the channel impulse response. In the whole process, the length of an optimal statistic window is self-adaptively determined according to the covariance coefficient of each tapping, the parameter required by the Bayes estimation is computed, thereby providing a complete and precise channel estimation parameter for a visible light communication system, and realizing the accurate estimation of the visible light channel.
Owner:SYSU CMU SHUNDE INT JOINT RES INST +1
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