343 results about "Approximation algorithm" patented technology

Systems and methods for tracking a wireless device are disclosed. According to one aspect, the wireless device includes a hybrid global positioning system (GPS) and wireless local area network (WLAN) circuit board for seamless indoor and outdoor tracking. In embodiments, GPS and WLAN data are combined to obtain a position estimate of the device. In other embodiments, the circuit board automatically switches between WLAN and GPS data for indoor and outdoor environments. A Location Based Services (LBS) algorithm for determining the position of a wireless device using WLAN and/or GPS signals is also disclosed. The LBS algorithm is implemented by way of method steps including: sensing GPS and/or WLAN signals, measuring and/or converting the sensed signals to obtain distance data, fusing the distance data, and applying one or more approximation algorithms to the distance data to obtain a position estimate of the wireless device. A method for rendering position data using a Marching Cubes algorithm is further disclosed.

Dynamically controlling and managing the power consumption and performance of energy consuming elements of a system to save energy while still providing the optimal system performance as required by the application(s) being executed. Both system performance and the applied system power are controlled by a specific convergence process which adjusts the system performance in real-time to the requirements of the application and the current operating situation.

An asynchronous analog to digital convertor for converting an analog input signal into a digital output is presented. According to an embodiment, the analog to digital convertor comprises a clock input operable to receive an external clock signal having a clock period, a comparator operable to compare the analog input signal to a reference signal, a digital to analog converter operable to generate the reference signal corresponding to a state of a successive approximation register, and a control block connected to the comparator and to the digital to analog converter. The control block is operable to generate and receive a sequence of control signals according to a successive approximation algorithm, to perform a plurality of comparisons, and to update the state of the successive approximation register thereby generating the digital output.

The invention discloses an SDN multi-controller deployment novel method for reducing management load overhead, belonging to the technical field of the software defined network (SDN). The method is characterized in that the management load of a software defined network (SDN) controller is used as a decision variable, and a mathematical model about controller management load is constructed. An original SDN network multi-controller deployment problem is abstracted to be a graph theory problem, the graph theory problem is converted into an integer linear programming problem through establishing the mathematical model, and an NP difficult problem is solved by using an approximate algorithm. According to the method, in the process of constructing the mathematical model of the multi-controller deployment problem, the network performance and the management load of the SDN controller are creatively taken into consideration, effective deployment schemes can be provided for different SDN networks, the reasonable selection and effective deployment of the number of multiple controllers are realized, and the normal and effective operation of the SDN network in the condition of the satisfaction of certain network performance and minimum cost are ensured.

Methods and systems for obtaining mass spectrographic data of a substance. Methods include subjecting a substance to a chromatographic process or other separating process, ionizing the output thereof, and subjecting the ionized output to recursive mass spectrometry analyses; and provide improved processing and analysis of data acquired during the repeated analyses. Systems according to one aspect of the invention comprise ion sources, mass spectrometers capable of analyzing ions of selected mass, and controllers adapted to receive from the mass spectrometers and retain signals representing data representing pluralities of mass spectrograms. The controllers can be adapted to generate information useful for describing extracted ion chromatograms, using data associated with the pluralities of mass spectrograms and non-linear curve approximation algorithms; and to use the generated information to generate further information useful in further analysis of the ionized substance.

An apparatus for transforming a signal strength of a wireless positioning system is provided. The apparatus is adapted for eliminating the difference of signal strengths between different mobile communication apparatuses or different environments. The apparatus includes a location estimation circuit. The location estimation circuit is adapted to obtain a possible coordinate by calculating a first signal strength distribution received by a mobile communication apparatus. The possible coordinate and the first signal strength distribution are taken as training data for training a transforming module with an approximation algorithm. Accordingly, the present invention adopts a positive correlation index and the approximation algorithm for automatically training a transforming module for the mobile communication apparatus without using the information of chip model and location of mobile communication apparatus.

The invention discloses a quantitative evaluation method for lateral sealing of a fault.The method is mainly based on the research about the fault sealing mechanism and influence factors thereof, under the circumstance that pressure bearing time of the fault is considered, a fault-reservoir displacement pressure difference method for quantitative evaluation of fault sealing is improved, and a fault sealing quantitative evaluation geological and teaching model taking the time factors into consideration is established.The gradual-approximation algorithm with the given step length is adopted, it is determined that rocks of a surrounding rock stratum have the same shale content as a target spot stratum and the burial depth at the diagenetic degree, then according to the relation between the product of the shale content of the rocks built in a research area and the burial depth and the displacement pressure, the displacement pressure of target spot stratum rocks is calculated quantitatively and compared with the displacement pressure of a target disc reservoir stratum, and whether the fault is sealed or not as well as the magnitude of the sealing capability are evaluated quantitatively.It is verified through actual data that when compared with a fault rock shale content (SGR) method and the fault-reservoir displacement pressure difference fault sealing evaluation method which does not consider pressure bearing time, the method has feasibility.

Data overhead of mesh-based multicast ad hoc routing protocols are controlled by adaptively adding redundancy to the minimal data overhead multicast mesh as required by the network conditions. The computation of the minimal data overhead multicast mesh is NP-complete, and therefore an heuristic approximation algorithm inspired on epidemic algorithms is employed to increase tractability of a solution. A mobility-aware and adaptive mesh construction algorithm based on a probabilistic path selection is provided, which is able to adapt the reliability of the multicast mesh to the mobility of the network. Simulation results show that the proposed approach, when implemented into On-Demand Multicast Routing Protocol (ODMRP), is able to offer similar performance results and a lower average latency, while reducing data overhead between 25 to 50% compared to the original ODMRP.

The invention discloses an electric power system power network planning method suitable for taking the wind power random characteristic into account includes the steps that a power network planning model taking wind power into account is constructed, limit scenes of random variable wind power output and loads are acquired, H test scenes of all the limit scenes of the output and the loads of a fan are acquired according to a Taguchi orthogonal table, variables in the Taguchi orthogonal table are horizontally converted into respective corresponding horizontal values, the horizontal value of each variable in each test scene is substituted into the power network planning model, and thus H sets of deterministic formulae are obtained; the H set of deterministic formulae are solved with an outer approximation algorithm in the MINLP problem, and then the final power network planning scheme is obtained. On the basis of obtaining the wind power output probability characteristic, the wind power output limit value is selected, the constructed model is solved through the outer approximation algorithm based on the Taguchi orthogonal table, then the electric power system power network planning method suitable for taking the wind power random characteristic into account is obtained, and thus it can be guaranteed that an electric power system can adapt to the randomness of wind power.

A method for identifying the approximate semantic content of digital objects is disclosed. Pursuant to the creation of a digital object, an approximation algorithm is used to compute the approximated semantic content of that object. This approximated content is then put into a normalized form. A hash function is used to compute a unique fingerprint for the resulting normalized, approximated object. This fingerprint is stored along with the object. The same approximation, normalization, and fingerprinting processes are used to generate a fingerprint for the digital object alleged to be semantically identical to the previous object. A match indicates that the alleged object and the previous object are approximately semantically identical. This verification method can be used to validate that a digital object has not been semantically altered, despite restructuring or reformatting of the object.

SAR with partial capacitor sampling to reduce parasitic capacitance. An analog-to-digital convertor is disclosed with reduced parasitic capacitance on the input during a sampling operation. A charge-redistribution, binary-weighted switched-capacitor array is included having a plurality of array capacitors that each have a commonly connected plate interfaced to a first common node and a switched plate, the switched plate operable to be switched between first and second reference voltages during a redistribution phase and select ones of the capacitors additionally operable to be switched to the input during a sampling phase. Each of the array capacitors has a parasitic capacitance associated therewith. A compensation capacitor having a common plate is connected to the first common node and a switched plate, the compensation capacitor operable to be switched to the input during the sampling phase and to the first reference voltage during the redistribution phase. The compensation capacitor has a parasitic capacitance less than the parasitic capacitance of the combination of all of the non select ones of the array capacitors. A comparator compares the voltage on the first common node to a compare reference voltage during the redistribution phase. A successive approximation controller is provided for switching the switched plate of the array capacitors between the first and second reference voltages in accordance with a successive approximation algorithm during the redistribution phase.

The invention relates to a method for adjusting the position and the size of a projection picture with the full degree of freedom. The method comprises the steps of projecting a standard testing image through digital light process (DLP); aiming at a projection screen and shooting the projection picture through CCD; acquiring the adjustment amount of a zoom adjustment to conduct zoom adjustment by processing of shot data by a computer; and sequentially using rotating adjustment, vertical inclination adjustment, horizontal displacement adjustment and vertical displacement adjustment as an adjustment object, loop executing of the following steps and completing the adjustment to the projection picture. The CCD is directed at the projection screen to shoot the projection picture, analyzing and processing are conducted on the shot data by using an approximation algorithm through the computer to obtain the adjustment amount and the adjustment direction corresponding to the adjustment object, and the computer automatically controls a corresponding knob to conduct adjustment. By means of the method for adjusting the position and the size of the projection picture with the full degree of freedom, the computer automatically controls the five shafts of six shafts to adjust the knob, so that the relative position of a light machine and the projection screen can be adjusted accurately, the projection image can be fully displayed on the screen inerrably, manual operation is needless, and time and labor can be saved.

The invention provides a fast calculation method of target electromagnetic scattering characteristics. The fast calculation method comprises the following steps: carrying out overall subdivision on an established geometric profile non-conformal grid model, selecting induced electromagnetic flow on an analog target surface of an electromagnetic basis function on a target subdivision grid, constructing impedance matrix elements by using a discontinuous Galerkin integral equation and boundary conditions, grouping the targets by using a tree block grouping strategy, accelerating a matrix-vector multiplication speed by using an adaptive cross approximation algorithm, iteratively calculating an electromagnetic flow inductance coefficient on the target surface under an irradiation source by using a generalized minimal residual method, calculating a radiation field of induced electromagnetic flow on the target surface, and obtaining secondary scattering field characteristic data. The fast calculation method provided by the invention has the advantages of strong adaptability and high calculation precision, greatly expands the calculation efficiency and the calculation ability of the integral equation, reduces the subdivision difficulty, and is easy for engineering.

An apparatus and method for testing a unit comprising of digital-to-analog converter and an analog-to-digital converter, by determining offset and gain-difference between the two converters, and then testing the pair using a wide range of values. During the testing, the gain-control is injected into the unit in order to set the unit size of one of the converters, and the offset is subtracted from the output signal of the unit, so that the transfer functions of the converters are matched. The gain-control is optionally determined using the successive approximation algorithm.

The invention provides a four-rotor aircraft speed control method based on integral variable structure control, and relates to the technical field of embedded systems, digital signal processing, microminiature unmanned aerial vehicles and the like. Firstly, building a four-rotor aircraft experimental platform, wherein the platform is an aircraft rack constructed by carbon fiber materials and a designed flight control embedded system; secondly, designing a flight control system by adopting a hierarchical designing scheme, wherein the flight control system comprises an upper-layer control module and a lower-layer control module; thirdly, achieving aircraft attitude control in the lower-layer control module, achieving speed control in the upper-layer control module; and fourthly, using an integral variable structure control algorithm in the attitude control and the speed control. According to the four-rotor aircraft speed control method based on the integral variable structure control, a prithvi air defence exercise (pade) approximation algorithm, a Kalman filtering algorithm and the integral variable structure control algorithm are used, algorithm complexity of the system is reduced greatly through the pade approximation algorithm; system state quantity which can not be obtained directly through sensors is obtained through the Kalman filtering algorithm; and lastly an integral variable structure controller is designed, wherein the integral variable structure controller has strong robustness and anti-interference performance.

The invention belongs to the field of hydropower dispatching and discloses a method for mixedly optimizing and dispatching a hydropower station group, power stations and units. The method includes firstly, adopting the power stations as basic dispatching units to optimize and calculate the hydropower station group to generate initial solution, solving and optimizing the initial solution; then adopting an in-factory economic running method in the power stations requiring output control to the units, distributing output of each unit at each time section by utilizing water consumption as the minimum standard under constraint of increasing and decreasing trend during total output process of hydropower stations; and finally, under support of basic regulating and controlling algorithm of the units, optimizing and dispatching the different power stations by taking the power stations or the units as basic dispatching units and utilizing successive approximation algorithm according to the requirement that whether regulation and control are refined to the units or not. Security constraint of the power grid is involved in the automatic control method, security of the power grid and control target of a centralized control center can be taken into consideration at the same time, organic connection of online real-time control and offline short-period dispatching plane is realized, and the requirements for control security, timeliness, practicality and economy can be met.

The invention discloses a multi-parameter rapid detection method and equipment for a water quality of household drinking water. With the adoption of a method combining test paper and a color sensor, in a sealed and dark condition, a stable light source emits white light to irradiate test paper to be detected; the test paper reflects the light of the color of the test paper to the color sensor; the color sensor converts a light signal into a pulse count; the pulse count is output to a single chip microcomputer and is processed by the single chip microcomputer; a database established through a standard reagent experiment is called; and a chloride ion concentration and a pH value of water can be detected by using a least value approximation algorithm. The water is converted to be a variable resistor by using an electrode through a voltage dividing, following and amplifying circuit; a voltage analogue quantity is converted into a digital quantity by using an A/D (Analogue/Digital) converter; and the digital quantity is transmitted to the single chip microcomputer for processing, so that the conductivity of the water is detected. The multi-parameter rapid detection method and equipment provided by the invention can be used for detecting the household drinking water; and the multi-parameter rapid detection equipment has a function of detecting various parameters, such as the chloride ion concentration, the pH value and the conductivity. The multi-parameter rapid detection equipment is simple in circuit, intelligent and accurate.

The invention belongs to the technical field of machine sight and provides an automatic extracting method for image features of straight chatoyancy by three steps. The invention extracts the sub-pixel image coordinate of the central points of the chatoyancy based on the chatoyancy center extracting method of Hessian matrix, connects the chatoyancy central points into a chatoyancy central line, then splits the chatoyancy central line into an approximative straight line at the knee of curve through a straight line approximate algorithm, and combines the colinear central points within the distance between the image origin points satisfying the angle limit and the approximative straight line, conducing straight line fitting for the combined colinear central points to acquire the parametric equation of the straight chatoyancy through straight line fitting. The three-step method disclosed in the invention realizes automatic extraction for image feature of the straight line chatoyancy in structure light under complicated background, eliminates the influence of stray interference feature, improves the automation level about the image feature extraction of the straight chatoyancy, makes full of all the chatoyancy central points on the straight chatoyancy and establishes a base for improving the rated efficiency and rated accuracy of an optical visual system and simplifying the field operation.

Disclosed is a method for determining the placement of ITAPs in wireless neighborhood networks. The method disclosed provides for efficient integration of multi-hop wireless networks with the Internet by placing ITAPs at strategic locations. Initially the method provides for the formulation of the ITAP placement problem under three wireless models. For each model, methods are developed to efficiently place ITAPs in the networks. The methods aim to minimize the number of required ITAPs while guaranteeing users' bandwidth requirements. Next, a fault tolerance version of the placement method is presented that provides bandwidth guarantees in the presence of failures. Finally the methods are extended to take into account variable traffic demands by developing an approximation algorithm to simultaneously optimize ITAP placement based on demands over multiple periods.

The invention relates to a feature selection method and a detection method of junk mails. The feature selection method of the junk mails includes the steps that features of the mails are extracted on the basis of a byte N-grams method; according to the relevancy between the extracted features and a preset mail type, the features are ordered, so that initial feature subsets are generated; according to the Markov blanket approximation algorithm, redundant features in the initial feature subsets are deleted, so that candidate feature subsets are obtained; the candidate feature subsets are predicated through an online logistic regression classifier and evaluated according to predication results, so that the optimal feature subset is selected; according to the selected optimal feature subset, the junk mails are detected through the online logistic regression classifier. By the adoption of the feature selection method and the detection method of the junk mails, the calculation processes for feature selection and detection of the junk mails are simple, time complexity is low, and therefore the junk mail detection accuracy is greatly improved.

The invention relates to a DC offset correction method of a zero intermediate frequency receiver. The method comprises the following steps that during an electrification initializing period of a receiver, a successive approximation algorithm digital processing module completes DC offset detection and stores detected DC offset values of I and Q components in a correction result storage unit; and every time the receiver carries out reception, the receiver automatically takes the DC offset values from the correction result storage unit, the DC offset values are converted into analog voltage signal via a DAC, the analog voltage signals are back fed to the input end of an analog amplifier, and DC offset correction is completed. A DC offset correction device of the zero intermediate frequency receiver comprises an analog amplifier, an analog converter, the successive approximation algorithm digital processing module, a switch K, a digital to analog converter (DAC) and the correction result storage unit connected sequentially; and the correction result storage unit is connected with the digital to analog converter. According to the invention, primary DC offset amount of the receiver is detected and stored in one step in the chip electrification initializing process of the receiver, and every time the receiver carries out reception, the stored DC offset values are loaded automatically, and are corrected before being input to the amplifier and the DAC.

The invention provides an automatic calibration method of a sensor and a batch calibration device. The automatic calibration method realizes automatic calibration of the sensor through two large links including pre-calibration and main calibration, wherein at a pre-calibration phase, configuration parameters of a sensor regulation chip of the sensor are calculated and determined; the main calibration comprises the steps of stabilizing sensor output to a needed output value through regulating a compensation amount on the basis of the pre-calibration and obtaining a calibration compensation value by adopting an approximation algorithm. Only external excitation with minimum and maximum measuring ranges needs to be applied for one time, calibration of the sensor can be finished; corresponding physical connection expansion can be carried out according to the quantity of a sensor system needing to be calibrated to perform batch calibration on the plurality of sensor systems.