137 results about "Linear search" patented technology

The subject matter described herein includes methods, systems, and computer readable media for adaptive packet filtering. One method includes identifying at least one subset of rules and an ordered set of firewall packet filtering rules that defines a firewall policy such that the subset contains disjoint rules. Disjoint rules are defined as rules whose order can be changed without changing integrity of the firewall policy. Rules in the subset are sorted to statistically decrease the number of comparisons that will be applied to each packet that a firewall encounters. Packets are filtered at the firewall using the sorted rules in the subset by comparing each packet to each of the sorted rules in the subset until the packet is allowed or denied and ceasing the comparing for the packet in response to the packet being allowed or denied and thereby achieving sub-linear searching for packets filtered using the sorted rules in the subset.

A method for fast and efficient record retrieval in large databases using cyclical redundancy check (CRC) computations as hash functions. Two hash values are computed for each record's key using the CRC-CCITT and CRC-16 generator polynomials. The two CRC values then are combined into a four-byte composite hash value that represents a binary signature of the record's key. Alternately, a single CRC-32 value can be used as a four-byte hash value. In most cases, this four-byte hash value uniquely identifies the record's key. An index file is constructed using a hybrid search method, part hash table and part linear search. The index file is searched to find a match for the four-byte hash value and the record's offset is obtained. The record's offset is used to retrieve the record from the database.

Systems and methods are provided for performing automated face recognition and comparison. An input image of a face may be received and cropped, and the image may be processed through a deep neural network (DNN) to produce a k-dimensional feature vector. The k-dimensional feature vector may be converted to a k-dimensional binary vector by transforming each value in the vector to either 1 or 0. To search for nearest matches of the image in a database of gallery images of faces, the system may compare sub-strings of the binary vector to hash tables created from sub-strings of the gallery images, enabling sub-linear searching that allows locating the closest matches from among the entire gallery without requiring an exhaustive linear search of the entire gallery.

The invention provides a linear search method of joint allocation of channel bandwidth and power in a non-orthogonal multiple access link. The method comprises the following steps: 1) providing, by abase station, data flow service for a mobile user through the non-orthogonal multiple access technology; 2) analyzing system characteristics to equivalently transform a problem; and 3) designing an efficient algorithm solution according to the characteristics of the finally converted problem, and finally substituting an output result of the algorithm to a top layer problem to obtain an optimal bandwidth and power allocation value. The invention provides a feasible and efficient optimization method that not only guarantees the data demand of mobile users, but also minimizes the total system resource consumption, so as to improve the utilization rate of system resources and optimize the configuration of system resources.

The invention discloses a data message storing method, a data message searching method and devices thereof. The data message storing method comprises performing a hashing process to data messages according to a linear hashing function and obtaining the first index information of the data messages; judging whether the depth of the current hash bucket is smaller than a set standard value of the bucket depth or not according to the first index information of the data messages, if so, the data messages being storied in the current hash bucket, if not, judging whether the depth of a related hash bucket of the current hash bucket as the related hash bucket rule defined is smaller than the set standard value of the bucket depth or not, if so, performing a quadratic hashing to the data messages according to the designed quadratic hashing function and setting a splitting label for the current hash bucket. The invention also provides a data message storing device, a data message searching method and a data message searching device. According to the invention linear searching times in a hash bucket is reduced and searching efficiency of data messages is improved.

The invention, which belongs to the technical field of underground medium speed model inversion of seismic exploration, relates to a full-waveform inversion method based on a seismic record integral. The method comprises: an observed seismic record is obtained, denoising processing is carried out, and a seismic wavelet is extracted; a simulated seismic record is calculated; time-domain integrating processing is carried out on the observed seismic record after denoising and the simulated seismic record; difference processing is carried out two groups of data after integrating to form a back transmission source, and a back transmission wave field; a forward transmission wave field is calculated; a gradient is calculated; a conjugate gradient is calculated; according to a linear searching method, a step length of iterative updating is calculated; a model correction value is calculated and a speed model is updated; and whether the updated model meets a given condition is determined; if so, a result is outputted; and if not, the updated speed model is used as a new initial speed model and calculation is started again. Therefore, a problem that the inversion is trapped into a local limit value problem because of lack of low frequency seismic data and thus inversion fails during full waveform inversion is solved.

Provided are a method and apparatus for normal reverse playback of GOPs of a bitstream stored in a storage medium from an X^th GOP. The apparatus includes an MPEG decoder which reads a first bitstream corresponding to the X^th GOP and an (X−1)^th GOP from the storage medium and which decodes pictures of the X^th GOP and reference pictures of the (X−1)^th GOP using the read bitstream, a frame buffer which stores the pictures decoded by the MPEG decoder, and a display block which displays the decoded pictures stored in the frame buffer, wherein during the normal reverse playback, the apparatus displays all the decoded pictures only once, and each display time of the decoded pictures displayed only once is the same. Accordingly, the apparatus can perform a linear search even during the normal reverse playback.

The invention discloses a joint inversion method based on magnetotelluric and DC resistivity data, and the method comprises the steps: determining an inversion region according to observation data, carrying out the subdivision to obtain an initial grid, and setting an initial value of an inversion parameter vector; performing Gaussian-Newton inversion iteration based on the current value of the inversion parameter vector to calculate a model change amount and a linear search step length, and then calculating an iterative update value of the inversion parameter vector; judging whether an inversion termination condition is met or not, and if not, carrying out next iteration; if so, judging whether a progressive grid inversion termination condition is reached or not, and if so, ending the inversion; and if not, carrying out refined subdivision on the grid cell, updating the inversion parameter vector value, and returning to carry out Gauss-Newton inversion iteration until inversion is finished. According to the invention, a joint inversion technology of inversion grid adaptive adjustment is researched and developed, the problem of multiplicity of solutions of joint inversion interpretation of a magnetotelluric method and direct current resistivity data is effectively reduced, and the joint interpretation accuracy is improved.

The invention discloses a full waveform joint inversion method for improving high steep structure velocity inversion efficiency, and belongs to the petroleum geophysical exploration field. The method comprises the steps: establishing an observation system by inputting the initial velocity field, the shot record and the focus wavelet; utilizing traditional reverse time migration to obtain the imaging result which is taken as a reflection coefficient model, and applying linear forward modeling and linear wave field back propagation; calculating the gradient directions of two prism waveforms and adding the gradient directions together to calculate the inverse gradient direction of the prism waveform, using the linear search method or a parabolic fitting method to calculate the updated step, and using the calculated gradient direction and step to update the velocity; using the conventional full waveform inversion method to update the velocity again, and determining whether or not to satisfy the error condition; if not, using the updated velocity as the input velocity, and updating the velocity again; and if so, outputting the inversion result. The full waveform joint inversion method for improving high steep structure velocity inversion efficiency reduces the dependency about whether the high steep structure information is missing in the initial model, and improves the inversion accuracy and efficiency for the high steep structure.

The invention discloses a static safety risk assessment method for an AC-DC hybrid micro-grid in island operation. The method comprises the following steps of: simulating the N-1 open-circuit fault ofthe AC-DC hybrid micro-grid in island operation with a given topology; performing a disconnection analysis to obtain an island system with the fault disconnected and the unrecoverable power loss loadin a fault area; establishing a probability distribution model of the random failure of an interlinking converter and a distributed generation device, the random output of an intermittent distributedgeneration device, and the load random fluctuation, performing Monte Carlo sampling to obtain a random input variable sample value; performing regional load-shedding operation on the island system toobtain the power loss load in a non-fault area, and performing conventional power flow calculation by using an accelerated LM algorithm with non-monotone linear search (ALMNL); and obtaining the probability distribution of each static safety risk indicator. The method of the invention can assess the static safety risk level of the AC-DC hybrid micro-grid in island operation, is an effective method for researching the static safety reliability of the AC-DC hybrid micro-grid in island operation, and provides technical support for the planning and operation of the AC-DC hybrid micro-grid.

The invention provides a method for precisely solving the length of an unstressed cable of a cable-stayed bridge. The length of the unstressed cable is solved by substituting the average value of the nodal force at the end of the stayed cable with a precise calculation method for the force at the end of the stayed cable, and by building a precise expression s0 of the length of the unstressed stayed cable and a characteristic parameter beta constraint equation of the stayed cable when a tensile force at the end of a tower is known without selecting the primary value of the length of the unstressed cable. The method comprises the following steps of: building the precise expression of the length of the unstressed stayed cable and the characteristic parameter beta constraint equation of the stayed cable when the tensile force Tj at the end of the tower is known, and solving the length of the unstressed stayed cable. The method has the advantages of solving the problem on the selection of the primary value of the length of the unstressed cable, with high convergence rate and small calculation error. Compared with the linear search, the dichotomy and the improved chord secant method for iteratively solving the length of the unstressed cable, the method of the invention greatly improves the solution precision and solution efficiency of the length of the unstressed stayed cable, so the method is of relatively high application value in practical projects.

The invention discloses an available transfer capability calculation method based on the improved multiple centrality-correction interior point method. Power system basic trend parameters are acquired, initialization is performed, the complementary gap d<Gap> is calculated and convergence judgment is performed, the disturbance factor mu is calculated, the prediction direction and the correction are solved through the prediction-correction interior point method, the complementary gap d(^)<Gap> after prediction-correction is solved and weighting judgment is performed, the optimal weight is obtained through linear search, the optimized Newton direction is calculated, multiple centrality-correction is performed by taking the prediction correction direction of the prediction-correction interior point method as the affine direction, and the original and dual variables are updated. According to the invention, in each iteration process, the weighting process is performed on the correction direction in the prediction correction process selectively, the optimal ratio of the correction direction in the total Newton direction is determined through linear search, and the optimize prediction correction direction is taken as the affine direction of multiple centrality-correction, so not only the problem of misconvergence when PCIPM is used to solve ATC due to the wrong correction direction can be solved, and but also the defect of less iterative step size when MCCIPM is used to solve the ATC problem can be overcome.

The invention discloses an orthogonal multilateral Hash mapping indexing method for improving massive data inquiring performance. The method comprises the following steps that firstly, Hash mapping is carried out on inquiring attributes of data records; secondly, a B+ tree is established on a first layer Hash value space, and linear searching is carried out on Hash mapping values; thirdly, Hash mapping is carried out on a first layer Hash barrel again through a second layer Hash function so as to reduce the data capacity in the Hash barrel; fourthly, pointer connection is established between the two adjacent layer Hash barrels, partitioning is stopped when the number of the Hush barrels exceeds a specified early-warning threshold value, and orthogonal multilateral Hash mapping indexing is completed. By means of the method, various data formats are compatible, physical storage of data is not changed, orthogonal multilateral Hash optimizing strategies are provided for serious imbalance and overflowing phenomena of the Hash barrels existing in orthogonal Hash indexing, and thus the complex inquiring performance for big data and the inquiring efficiency of the data are improved.

A method and system for determining Psuedo-Noise (PN) composite phase is provided. The method includes providing at least three relatively prime PN component codes and partially correlating a received PN composite encoded signal with one of the PN component codes. The method also includes partially correlating the received PN composite encoded signal with a second one of the PN component codes while maintaining phase alignment of the first partially phase aligned PN code through the use of normalized autonomous phase numbers (NAPNs). The received PN composite encoded signal is then phase aligned with a receiver PN composite code phase in steps of epoch lengths of the partially phase aligned PN component codes.

An energy efficiency optimization transmitting power control method with quality-of-service guarantee in D2D communication comprises the following steps: (1) achieving the goal of D2D communication user energy efficiency optimization under the premise of guaranteeing the quality of service through control on the transmitting power of D2D communication users and cellular network users, and modeling the problem on the basis; (2) equivalently converting an optimization problem P1 involving transmitting power control on the D2D communication users and the cellular network users into an optimization problem P2 only involving the transmitting power of the D2D communication users by introducing auxiliary variables; and (3) converting the optimization problem P2 into an optimization problem P3 through analysis, and solving the optimization problem P3 by a one-dimensional linear search algorithm with hierarchical thinking. The invention provides an energy efficiency optimization power control method with quality-of-service guarantee in D2D communication, which can effectively reduce the load of a base station, increase the spectrum utilization rate, and alleviate the problem of spectrum resource scarcity of a wireless communication system.

The invention discloses a method of rapidly calibrating power of a high-precision radiofrequency signal source; the method comprises the steps of S1, allowing a control computer to control, through Ethernet, a broadband radiofrequency signal source to be calibrated to output single-tone signals having different frequencies and powers; S2, allowing the control computer to read, through the Ethernet, power measurement results in a calibration spectrometer; S3, allowing the control computer to set output signal frequency and output power for the radiofrequency signal source; allowing the calibration spectrometer to measure the frequency and power of an output signal and reports to the control computer through the Ethernet; allowing the control computer compares the set power value with the measured value of the spectrometer; when the output power precision of the radiofrequency signal source is unsatisfactory, allowing the control computer to adjust the output power of the radiofrequency signal source by means of combined radiofrequency gain and digital gain adaptive spacing search method until the test result of the spectrometer is satisfactory or test is time out, and recording final power setting parameters of the radiofrequency signal source. Compared with linear search methods, the adaptive spacing search method has lower calibration load and greatly shorter calibration time under wide-range frequency domain coverage.

The invention discloses a non-orthogonal multiple access based mobile edge computing linear search type time delay optimization method in multiple base station scenarios. The method comprises the following steps: (1) describing the optimized problem as a problem of multi-variable non-convex optimization when 1 mobile user exists under the coverage range of BSs of an integrated edge server; (2) resolving the problem (DM-i) into a problem of two-level optimization; (3) proposing a Lagrange multiplier method based bi-search method according to a bottom level DM-i-E-Sub problem, to optimize an overall time delay of the mobile user i in the case of the mobile user i with a transmission time t; (4) proposing a linear search method aiming at a top level DM-i-E-Top problem, to optimize the transmission time t of the mobile user i; (5) finally solving the problem (DM-i) through an interactive iteration of the bottom level problem and the top level problem. According to the non-orthogonalmultiple access based mobile edge computing linear search type time delay optimization method in multiple base station scenarios, the system transmission efficiency is improved, the bandwidth resources are saved, and a better wireless network experience is obtained.