158 results about "Iterative design" patented technology

Knee prostheses featuring components that more faithfully replicate the structure and function of the human knee joint in order to provide, among other benefits: greater flexion of the knee in a more natural way by promoting or at least accommodating internal tibial rotation in a controlled way, replication of the natural screw home mechanism, and controlled articulation of the tibia and femur respective to each other in a more natural way. In a preferred embodiment, such prostheses include an insert component disposed between a femoral component and a tibial component, the insert component preferably featuring among other things a reversely contoured postereolateral bearing surface that helps impart internal rotation to the tibia as the knee flexes. Other surfaces can also be specially shaped to achieve similar results, preferably using iterative automated techniques that allow testing and iterative design taking into account a manageable set of major forces acting on the knee during normal functioning, together with information that is known about natural knee joint kinetics and kinematics.

Knee prostheses featuring components that more faithfully replicate the structure and function of the human knee joint in order to provide, among other benefits: greater flexion of the knee in a more natural way by promoting or at least accommodating internal tibial rotation in a controlled way, replication of the natural screw home mechanism, and controlled articulation of the tibia and femur respective to each other in a more natural way. In a preferred embodiment, such prostheses include an insert component disposed between a femoral component and a tibial component, the insert component preferably featuring among other things a reversely contoured posterolateral bearing surface that helps impart internal rotation to the tibia as the knee flexes. Other surfaces can also be specially shaped to achieve similar results, preferably using iterative automated techniques that allow testing and iterative design taking into account a manageable set of major forces acting on the knee during normal functioning, together with information that is known about natural knee joint kinetics and kinematics.

Methods and compositions are provided that are useful for detecting and reporting a plurality of different target polynucleotide sequences in a sample, such as polynucleotides corresponding to a plurality of different genes expressed by a cell or cells. In particular, the invention provides methods for screening a plurality of candidate polynucleotide probes to evaluate both the sensitivity and the specificity with which each candidate probe hybridizes to a target polynucleoide sequence. Candidate polynucleotide probes can then be ranked according to both their sensitivity and specificity, and probes that have optimal sensitivity and specificity for a target polynucleotide sequence can be selected. In one embodiment, polynucleotide probes can be selected according to the methods described herein to prepare “screening chips” wherein a large number of target polynucleotide sequences are detected using a single microarray have a few (e.g., 1–5) probes for each target polynucleotide sequence. In a particularly preferred embodiment, the invention provides a screening chip that can detect genetic transcripts from the entire genome of an organism. In an alternative embodiment, polynucleotide probes can be selected according to the methods described herein to prepare “signature chips” to more accurately detect certain selected “signature genes” using several polynucleotide probes (e.g., 10–20) for each signature gene. The invention additionally provides microarrays containing polynucleotide probes for a large number of genes expressed by a cell or organism. Further, methods for detecting a plurality of polynucleotide molecules, including a large number of genes expressed by a cell or organism, are also provided.

The invention provides methods for designing contact lenses in which method the lens flexure is taken into account. The method of the invention is insensitive to the lens' back surface design and does not require complex back surface designs. Additionally, the lens design can be optimized virtually, eliminating the need for iterative design-test on-eye-re-design cycles.

Methods and systems automate an approach to provide a way to convert a circuit design from a synchronous representation to an asynchronous representation without any designer or user interaction or redesign of the synchronous circuit. An optimized, automated, non-Interactive conversion of representations of synchronous circuit designs to and from representations of asynchronous circuit designs, facilitating traditional electronic design automation (EDA) tools to process and manipulate asynchronous designs while allowing synchronous designs to be implemented using asynchronous hardware solutions. The invention also facilitates feedback to synchronous design tools in synchronous representation for optimization and iteration of the design process by engineers, eliminating the need for engineers to be aware of the underlying asynchronous architecture of the underlying hardware implementation.

Detection for a MIMO (multiple-input, multiple-output) wireless communications system with symbols iteratively detected in subsets with maximum likelihood hard decisions within subsets. Previously detected subsets of symbols are used to regenerate corresronding input signals for interference cancellation. With a 4-transmitter antenna, 4-receiver antenna system, two subsets of two symbols are possible with the first two symbols detected with zero-forcing or MMSE soft estimates which feed maximum likelihood hard decisions; and the hard decision for the first two symbols are used for interference cancellation followed by zero-forcing or MMSE soft estimates for the second two symbols which then feed further maximum likelihood hard decisions.

Techniques for an iterative design process of determining a visual representation for an input media object are provided. One or more visual representations are determined from the input media object based on a set of encoding parameters. An output media object is then created from the one or more visual representations based on a set of decoding parameters. The one or more visual representations and / or the second media object may be displayed to a user. An indication indicating whether one or more visual representations and / or the second media object is acceptable or unacceptable is then received. If the one or more visual representations and / or the second media object is not acceptable, then at least one parameter in at least one of the set of encoding parameters and the set of decoding parameters may be changed. The process described above is then repeated until the one or more visual representations and the second media object is determined to be acceptable.

Method for reducing the time needed to perform geophysical inversion by using simultaneous encoded sources in the simulation steps of the inversion process. The geophysical survey data are prepared by encoding (3) a group of source gathers (1), using for each gather a different encoding signature selected from a set (2) of non-equivalent encoding signatures. Then, the encoded gathers are summed (4) by summing all traces corresponding to the same receiver from each gather, resulting in a simultaneous encoded gather. (Alternatively, the geophysical data are acquired from simultaneously encoded sources.) The simulation steps needed for inversion are then calculated using a particular assumed velocity (or other physical property) model (5) and simultaneously activated encoded sources using the same encoding scheme used on the measured data. The result is an updated physical properties model (6) that may be further updated (7) by additional iterations.

An aspect of the present invention computationally determines the metal density of each metal layer supporting a power grid structure providing power to the elements of an integrated circuits. The metal densities are computed such that the power grid would support aggregate power and IR drop constraints. The metal densities thus computed are provided as inputs to a router block, which places the grid structure along with the signal paths on the layout of the eventual integrated circuit sought to be fabricated. Due to the computation of the metal densities upfront and providing to the router block, the iterative design of the IC might be avoided.

A decoder for performing soft decision iterative decoding of a cyclic code based on belief propagation, includes an information exchange control unit, an X processor, and a Z processor. The information exchange control unit takes pix-metrics that were calculated by the X processor for nonzero elements in each of n-cyclic shifts of the parity-check polynomial of the code, and distributes the pix-metrics to the Z processor as the piz-metrics for a corresponding check node. The information exchange control unit takes lambdz-metrics that were calculated by the Z processor for nonzero elements in each of n-cyclic shifts in a reverse order of the parity-check polynomial, and distributes them to the X processor as lambdx-metrics for the corresponding code node. The operation of the information exchange control unit can be represented by the Tanner graph associated with an extended parity-check matrix, which is produced by adding k rows to the parity-check matrix of the cyclic code, wherein the X processor functions as the code nodes and the Z processor functions as the check nodes.

Systems and methods for error recovery are presented. Data is decoded with an iterative decoding scheme having a first set of parameters. In response to a determination that the iterative decoding scheme has failed, the data is re-read. While the data is being re-read, the iterative decoding scheme is reconfigured with a second set of parameters, and the data is decoded with the reconfigured iterative decoding scheme. In response to determination that the reconfigured iterative decoding scheme has failed, an error type associated with the data is determined. An error recovery scheme is selected from a plurality of error recovery schemes for the data based on the determined error type.

A method that incorporates a detailed, precise procedure of designing a user interface by utilizing agent behavioral models. This method applies quantitative and qualitative agent behavioral models derived through the Categorize Describe-Model (CDM) methodology to the iterative design stage of interface development. The method includes: (1) categorizing at least two users; (2) validating targeted user behaviors and preferences; (3) capturing emergent behaviors and preferences; (4) tracking design requirements and implementations; (5) accommodating diversity in performance and preference during interactive testing; and (6) customizing a user interface design to each of the at least two users.

The invention relates to a sequence radial basis function agent model-based high-efficiency global optimization method, and belongs to the technical field of multidisciplinary optimization in engineering design. The method comprises the following steps of: according to initial conditions given by a user, selecting sample points in a primary iteration design space, calculating a response value of a true model, constructing a radial basis function agent model, calculating the current optimal solution of the radial basis function (RBF) agent model, calculating a response value of the possible optimal solution of the current iteration in the true model, judging whether the global optimization method meets the convergence criterion, determining an important sampling space of the next iteration, increasing new sample points in the constructed important sampling space by an experimental design calculation method, saving the new sample points in a design sample point database and making k equal to k+1, and switching to the constructed radial basis function agent model for the next iteration. Through the method, the true models in the engineering design and analysis software are approximated, and the optimization design of the true models only takes several or dozens of seconds, so the period of the engineering optimization design is greatly shortened, the design cost is greatly saved and the efficiency is obviously improved.

This invention provides a relay precoder selection method for two-way amplify-and-forward multiple-input multiple-output (MIMO) relay systems and communication devices using the selection method or the selected relay precoder. According to the relationship between a relay precoder and the singular values of the effective MIMO channels, a set of candidate relay precoders are constructed based on the singular vector subspaces of cascaded MIMO channels, and one of them is selected for meeting a specific design criterion, such as the minimum sum of mean-squared errors, the maximum sum of channel capacities, and the minimum or maximum sum of condition numbers, where the condition number is defined as the ratio of the largest to the smallest singular value of a MIMO channel. As compared with the iterative design methods with the best performance, this invention achieves close performance while requiring much lower computational complexity.

Methods and systems automate an approach to provide a way to convert a circuit design from a synchronous representation to an asynchronous representation without any designer or user interaction or redesign of the synchronous circuit. An optimized, automated, non-Interactive conversion of representations of synchronous circuit designs to and from representations of asynchronous circuit designs, facilitating traditional electronic design automation (EDA) tools to process and manipulate asynchronous designs while allowing synchronous designs to be implemented using asynchronous hardware solutions. The invention also facilitates feedback to synchronous design tools in synchronous representation for optimization and iteration of the design process by engineers, eliminating the need for engineers to be aware of the underlying asynchronous architecture of the underlying hardware implementation.

Systems and methods for multi-stage signal detection in MIMO transmission including Bernoulli-Gaussian detection are provided. A multistage iterative signal decoder is provided that exploits the property that in a relatively simply decoding scheme such as mean square error (MSE) or zero-forcing (ZF) only a small portion of the total symbols are mis-detected. Therefore, an optimality test is performed on the output of a relatively low complexity decoder unit. If the symbol passes the optimality test, it is presumed to be correctly decoded. Otherwise, the symbol is sent for further processing to a relatively higher complexity decoding unit such as a sphere decoder. In this way, processing efficiency is increased, because only those symbols requiring additional processing are processed by the high complexity processing unit.

For coherent fiber optic communications, the nonlinear XPolM impairment is the most important issue to realize over-100 Gbps high-speed transmissions. A method provides a way to cancel time-varying XPolM crosstalk by introducing multi-stage adaptive mechanism. In the method, a low-complexity adaptive filtering based on recursive least-squares (RLS) first tracks the time-varying crosstalk along with the per-survivor trellis-state decoding. The estimated channel and the decoded data are then used to calculate the empirical covariance, which is in turn exploited to obtain more accurate channel estimates by means of optimal-weighted least-squares. This is performed with a low-complexity processing over frequency domain with fast Fourier transform. The performance is significantly improved with turbo principle decoding, more specifically, iterative decoding and iterative estimation over a block.

A method and system for flow propagation analysis uses ‘tracers’ that are iteratively propagated through a simulated network between source and destination elements. These tracers are structured to contain traffic flow information from source to destination, and to reflect changes as the flow is affected by each element along the path from source to destination. The resultant flow information at the destination corresponds to the effective throughput from the source to the destination, and the flow information at the output of each intermediate element in the network corresponds to the potentially achievable throughput through that element for the given source-to-destination flow.

Iterative decoder employing multiple external code error checks to lower the error floor and / or improve decoding performance. Data block redundancy, sometimes via a cyclic redundancy check (CRC) or Reed Solomon (RS) code, enables enhanced iterative decoding performance. Improved decoding performance is achieved during interim iterations before the final iteration. A correctly decoded CRC block, indicating a decoded segment is correct with a high degree of certainty, assigns a very high confidence level to the bits in this segment and is fed back to inner and / or outer decoders (with interleaving, when appropriate) for improved iterative decoding. High confidence bits may be scattered throughout inner decoded frames to influence other bit decisions in subsequent iterations. Turbo decoders typically operate relatively well at regions where the BER is high; the invention improves iterative decoder operation at lower BERs, lowering the ‘BER floor’ that is sometimes problematic with conventional turbo decoders.

The invention discloses a modeling system which is used in reactor design and used for reactor core component design. According to the modeling system, the geometric specificity of a fission reactor core is analyzed, a great amount of repeatedly constructed geometries are adopted, a CAD engineering model and a Monte Carlo calculation model of the fission reactor core are automatically established by establishing parameters, the Monte Carlo calculation model is used for radiating and transporting input of a Monte Carlo calculation program, and the significant physical quantity of the reactor core can be calculated after the Monte Carlo calculation model is obtained. By constantly evaluating the physical parameters of the calculation result, the modeling system can be used for performing repeated iteration correction on a design scheme of the fission reactor core till a reactor core scheme which makes a user satisfactory is made. The modeling system has the benefits that the tediousness that Monte Carlo calculation programs are written and files are input manually is avoided, the whole modeling process is very visible, the probability of mistakes is greatly reduced, and the design time of the reactor core is shortened.

The invention discloses a method for designing a structure of a low-cost test combustion chamber with reliable thermal protection. The combustion chamber comprises a body barrel segment, a connecting flange, a nozzle part, a connecting bolt and a measuring filler neck part. The combustion chamber adopts a capacitive type structure; the body barrel segment is made of a pure copper material with a high thermal conductivity; and the nozzle part is made from a copper-infiltrated tungsten material. In the invention, a thermal analysis aided design method is required to be used firstly, which needs to establish a computation mode and a computing method at first and then perform an iterative design process of the structural design and the thermal analysis. The computation mode adopts an unsteady thermal-dimensional heat conducting differential equation and the computed heat exchange mainly comprises heat convection from the gas to the chamber wall and the radiant heat exchange, the heat conduction in the chamber wall, the convection from the chamber wall to the outside and the radiant heat exchange. The thermal analysis aided design method comprises a global computing analysis and a local correcting and computing analysis. The method can minimize the materials used under the condition that the combustion chamber has the reliable thermal protection and greatly reduce the cost.

The invention discloses an M-APSK (amplitude phase shift keying) signal to noise ration estimation method based on iterative decoding and decision feedback. The method includes subjecting a transport signal to utilize a variable bit rate decoder to obtain feedback result, modulating to obtain a receiving signal without noise, finding out relative position of the receiving signal on a constellation map, dividing into a plurality of circular rings, obtaining each circular ring receiving signal through solving rotation, calculating amplitude mean value of each circular ring receiving signal, calculating useful signal total power and transport signal total power according to the amplitude mean value, and calculating estimated value of signal to noise ratio. The concept of iterative estimation is adopted, iterative decoding output information bit is used for inverse modulation and constellation map division, and the data-aided algorithm is adopted to finish estimation of the signal to noise ratio, so that the problem of major errors in the constellation map division is solved, signal to noise estimation accuracy is improved, the problem of realizability and complexity brought by the maximum likelihood estimation method is avoided, and the M-APSK signal to noise ration estimation method based on iterative decoding and decision feedback has better application prospect.

An object-oriented computing environment stores information relating to objects in a data file, and manipulates the information in the data file through a suitable user interface. The interface permits a user to completely redesign a program structure by adding or removing parents of an object through simple actions such as menu commands or drag and drop operations. The precedence of parents in a heterarchy can be reordered, again through drag and drop operation. A new parent can be spliced between an existing parent and its children. Properties and handlers can be moved to appropriate levels of the program structure through simple operations, and the user can be provided with choices to make appropriate functionality changes to individual objects, as desired.

The invention discloses an iterative design method for a hypersonic-velocity aircraft model. The method comprises the steps that a parameterized model of a hypersonic-velocity aircraft is built through a geometric design method; a key model parameter of the hypersonic-velocity aircraft is extracted through a sensitivity approach, the parameterized model is simplified, and a surrogate model of the hypersonic-velocity aircraft for the iterative design is obtained; the model parameter of the hypersonic-velocity aircraft is optimized by using a pigeon-inspired optimization algorithm, and the balance states of the model in different flight conditions are obtained; a desired performance index of the hypersonic-velocity aircraft is determined, the balance states of the model are subjected to iteration, and the optimal design model of the aircraft is obtained. In complex flight conditions, the optimal design model is obtained by using the pigeon-inspired optimization algorithm according to the desired performance index, the optimal model parameter meeting the desired performance index is quickly obtained, all flight envelopes can be covered, and a good model optimizing tool is provided for the design of the hypersonic-velocity aircraft.

A trim control design method for a high speed helicopter with a coaxial thrust rotor is provided. At first, that balan equations of the airframe degree of freedom are established, Aiming at the multi-round iterative design process of trim manipulation, 6 manipulator and 2 attitude angles are use as trim variables, The trimming of the small speed segment, the transition velocity segment and the large velocity segment are respectively performed from the angle decoupling of the vertical and horizontal variables, the influence of the variable on the strength and weakness of the equilibrium equation, and the increase of the equality constraint. balancing the same number of variables and equations in each round of balancing, the previous round of balancing provides the necessary parameter basisfor the next round of balancing, progressing step by step, checking and correcting, and completing the balancing after four rounds of calculation. The present application reduces the calculation time,facilitates the engineering application of the trim control design method, and improves the practical value of the design method.

The invention discloses an iterative demapping and decoding method and an iterative demapping and decoding system. The iterative demapping and decoding method comprises the following steps: step 1, a control unit and arithmetic units are initialized, wherein the arithmetic units comprise a demapper, a variable node decoder and a check node decoder; step 2, when the demapper reaches a starting condition, decoding procedures are started by the control unit; step 3, the decoding procedures are operated under the control of the control unit, at least part of the arithmetic units executes respective operation concurrently; and step 4, when a decoding stop condition is reached, the decoding procedures are stopped by the control unit, and code words of decoding results are output. The iterative demapping and decoding system comprises the control unit, a storer, the demapper, the variable node decoder and the check node decoder for achieving the method. The iterative demapping and decoding method and the iterative demapping and decoding system can solve the problems that operating efficiency is low, complexity is high, handling capacity is limited and the like in an actual system.

The invention provides a method for constructing LDPC (low density parity check) codes based on row-column combined iterative decoding, comprising the following steps: 1, initializing parameters of the LDPC codes; 2, setting an operation sequence of rows (block rows); and 3, using a Peg or (Block-Peg) algorithm to construct an H matrix of the LDPC codes [QC (quasi-cyclic)-LDPC codes], wherein when positions of nonzero elements (sub-blocks) are determined, that is, when the connection of bipartite graphs of the H matrix is determined, the condition met: any two check nodes in all connected check nodes at the same variable node are not adjacent under an arrangement sequence determined in the step 2. The nonzero blocks in the two adjacent rows under the operation sequence of the rows of the constructed LDPC codes are not in the same column, thus reducing the time delay of information updating between the rows when hardware is realized, and improving the decoding rate.

The invention provides a self-adaptive iterative decoding method for Turbo product codes. The self-adaptive iterative decoding method comprises the steps as follows: channel environment values obtained through simulation and simulation samples of corresponding iterative factors are stored in a storer; the channel environment values S are estimated according to soft information R output by a demodulation terminal; corresponding groups of most suitable iterative factors are selected according to different channel environment values S; then the soft information R and the selected iterative factors are sent into a Turbo code soft-input soft-output (SISO) iterative decoder to be decoded; a code word of the current time of decoding is detected by an iterative stopping judging unit and compared with a code word of the last time of decoding; and when the distance between the code word of the current time of decoding and the last time of decoding is smaller than or equal to an iterative threshold, the decoding is stopped and the code words are output, otherwise iterative decoding is continued. The self-adaptive iterative decoding method has the advantages that suitable iterative factors can be selected according to different channel environments to realize optimal decoding, the iterative times are selected in a self-adaptive manner, and power consumption of a receiver is effectively reduced.

The invention discloses a method for estimating the size parameter of a carrier rocket, belongs to the technical field of aerospace and aims to solve the technical problem of large calculation amountand inaccuracy during conventional size parameter selection. The method for estimating the size parameter comprises the following steps of: carrying out task index analysis, selecting an overall scheme and determining each system parameter; determining design variables, an optimization target and constraint conditions and building a corresponding mathematical model on the basis of a size parametermodel, wherein the size model comprises a part size calculating module, an engine size calculating module and an overall size calculating module for sequential calculation; carrying out size parametric modeling on the carrier rocket, writing an integrated calculation program and giving input and output files; selecting an optimization algorithm, inputting to an optimizer and selecting a size parametric model to obtain a reference design scheme. The method disclosed by the invention has the advantages that the iterative design times of the carrier rocket in the overall scheme stage is reduced;and the method is simple in process, small in calculation amount and high in efficiency.