350 results about "Sigmoid function" patented technology

In layered VDR coding, inter-layer residuals are quantized by a non-linear quantizer before being coded by a subsequent encoder. Several non-linear quantizers are presented. Such non-linear quantizers may be based on sigmoid-like transfer functions, controlled by one or more free parameters that control their mid-range slope. These functions may also depend on an offset, an output range parameter, and the maximum absolute value of the input data. The quantizer parameters can time-vary and are signaled to a layered decoder. Example non-linear quantizers described herein may be based on the mu-law function, a sigmoid function, and / or a Laplacian distribution.

The invention relates to a method of real-time detection for the spot welding nugget diameter of an aluminium alloy resistance, which includes the following steps:1. acquiring the electrode displacement signals in the process of spot welding and drawing the curve diagram of the electrode displacement signals;2. extracting the two eigenvalues of expansion displacement and forging displacement;3. unripping the aluminium alloy welding board, measuring the spot welding nugget diameter of the resistance and constructing a couple-sample corresponding to the extracted eigenvalues and the measured nugget diameters;4.repeating the steps 2 and 3 so as to obtaining the couple-samples with the required quantity for design; 5.constructing an artificial neural network model and carrying out training with the obtained couple-samples according to BP algorithm so as to realizing the mapping from the eigenvalue to nugget diameter, wherein the artificial neural network model has two inputs, one output and an implicit strata in the middle, which has five nodes and the transfer function of which is Sigmoid function, and the transfer function of the output layer is linear function; 6.applying the trained model to the real-time detection for the spot welding nugget diameter of an aluminium alloy resistance.

An apparatus, system, and method are disclosed for predictive control of a turbocharger. The method includes interpreting a compressor performance model for a turbocharger, and interpreting at least one current operating parameter. The method further includes calculating a performance margin, calculating a performance margin derivative, and calculating a response value. The performance margin comprises a choke margin or a surge margin according to the position of an operating point in the compressor performance model. The performance margin is implemented in a first sigmoid function, and the performance margin derivative is implemented in a second sigmoid function. The response value is determined by applying a MIN function to the output of the product of the sigmoid functions in the choke margin case, and by applying a MAX function to the product of the sigmoid functions in the surge margin case.

The invention discloses a method for selecting an access network in a heterogeneous network. The method includes the following steps: building of a non-cooperative game model between a user and a network according to a game theory method; model solution which determines an optimizing strategy for balancing mutual interest of the network and the user; and experiment simulation and numerical analysis. A non-monotone network service quality quantization model is built by combining a gray level relevance idea and a sigmoid function in a robot study mechanism. Simulation shows that the model fits an actual heterogeneous fusion network scene, according to the non-cooperative game model between the user and the network, the strategy of balancing the mutual interest of the user and the network is adopted, and a network optimization pricing strategy is determined by solving the non-cooperative game model. In addition, the method helps the user to select the most suitable access network, accordance is provided for formulating a QoS standard of the heterogeneous network fusion system, and service requirements of different levels of the user under different scenes are met.

The invention discloses a sliding-mode variable structure control method of a variable exponential coefficient reaching law of a permanent magnet synchronous motor. The method comprises the following steps: aiming at the requirements of a control system of a high-performance permanent magnet synchronous motor, a variable exponential function term formula is introduced on the basis of a conventional exponential reaching law; the formula takes a first-order norm of systematic state variables as an exponent of exponential functions, adaptively adjusts the reaching speed of a variable exponent term and a variable speed term according to the distance between the system and a sliding-mode surface, and is helpful to increase the dynamic response speed of the system; the systematic state variables are associated by taking the first-order norm of the systematic state variables as the exponent of the functions; and an s function is introduced to replace a symbolic function for further suppressing system chattering. Therefore, the sliding-mode variable structure control method of the permanent magnet synchronous motor using the variable exponential coefficient reaching law is provided. Compared with an integral-type sliding-mode variable structure control method, the method disclosed by the invention can be used for effectively increasing the dynamic characteristics and steady state characteristics of the system as well as increasing the robustness of the system.

A method for calculating a neuron layer of a multi-layer perceptron model that includes a permanently hardwired processor core configured in hardware for calculating a permanently predefined processing algorithm in coupled functional blocks, a neuron of a neuron layer of the perceptron model being calculated with the aid of an activation function, the activation function corresponding to a simplified sigmoid function and to a simplified tank function, the activation function being formed by zero-point mirroring of the negative definition range of the exponential function.

The invention relates to a detecting method of the rotor position and rotating speed of a permanent magnet synchronous motor, and belongs to the field of permanent magnet synchronous motor control. The detecting method includes the following steps that a counter electromotive force equation and a state equation of the permanent magnet synchronous motor are set up; matrix-vector arrangement is carried out on the state equation set up, and a state estimating equation is set up according to the state equation obtained after arrangement to obtain a state error equation; a second-order sliding-mode observer equation is set up according to the state error equation to obtain a counter electromotive force error equation; the sigmoid function is used for replacing the control function signum to correct the counter electromotive force error equation; a counter electromotive force estimating equation is set up according to the counter electromotive force error equation obtained after correction; the counter electromotive force estimating equation is subtracted from the counter electromotive force equation, the Lyapunov equation is used for analyzing stability to obtain and correct a rotor rotating speed estimating equation; rotor position information is extracted through the phase-locked loop technology. A model reference adaption and second-order sliding-mode combined observer is used for estimating counter electromotive force and rotor speed of the permanent magnet synchronous motor and replacing a traditional sliding-mode observer to obtain the rotor speed through counter electromotive force numerical calculation.

global stress constrained topology optimization method for compliant mechanisms based on K-S function is presented. The method comprises the following steps: (1) defining a design domain and initializing design variables; (2) punishing the stiffness of the structural element and obtaining the displacement and stress of the structure by the finite element method; (3) Using K-The S function condenses the local stress constraints of all elements into a global maximum stress constraint. (4) sloving Sensitivity of cross-strain energy objective function, sensitivity of volume and maximum stress constraint; 5) modifying that sensitivity of the sensitivity filtering technology; (6) Moving asymptotic algorithm is used to solve the optimization problem, and the optimal topology is obtained by iterating until the convergence criterion is satisfied. The S-function condenses the large number of constraints caused by the stresses in all elements into a global constraint, which greatly improves the computational efficiency. The topology optimization method of the invention enables the compliant mechanism configuration to avoid the hinge-like structure, meets the strength requirements, and alleviates the stress concentration phenomenon.

The invention administers an objective clinical test to an eye that measures the visual sensitivity of the superior retina and the inferior retina, by alternately presenting a stimulus pair comprising a shaped superior light stimulus and a shaped inferior light stimulus that are horizontal mirror images of one another and have shapes encompassing visual field defects. The shaped superior and inferior light stimuli stimulate pupillary responses whose amplitudes are measured. A cycle-averaged pupillary response balance and a luminance ratio are computed for each presentation of a stimulus pair. A stimulus pair response curve is computed by fitting cycle-averaged pupillary response balances to a sigmoid function of the luminance ratios. A balanced luminance ratio at which the cycle-averaged pupillary response balance is equal to about zero is computed from the sigmoid function. The balanced luminance ratio is indicative of the presence and location of retinal nerve damage.

Systems and methods for identifying and removing spikes in data sets representing PCR growth curves or other sigmoid type curves or growth curves. A double sigmoid function with parameters determined using a Levenberg-Marquardt regression algorithm is used to find an approximation to the curve, and a statistical test such as a z-test is then used to identify spikes by identifying data points in the data set that do not fit well with the approximation. The identified spike(s) are removed from the data set and / or replaced with interpolated data points determined by using data points surrounding the identified spike(s). In one aspect, a spline interpolation process such as a cubic spline interpolation process is used to find an approximation to the data set with the identified spike points removed. Interpolated values to replace the spike points are then calculated using the cubic spline interpolation approximation curve.

An apparatus, system, and method are disclosed for predictive control of a turbocharger. The method includes interpreting a compressor performance model for a turbocharger, and interpreting at least one current operating parameter. The method further includes calculating a performance margin, calculating a performance margin derivative, and calculating a response value. The performance margin comprises a choke margin or a surge margin according to the position of an operating point in the compressor performance model. The performance margin is implemented in a first sigmoid function, and the performance margin derivative is implemented in a second sigmoid function. The response value is determined by applying a MIN function to the output of the product of the sigmoid functions in the choke margin case, and by applying a MAX function to the product of the sigmoid functions in the surge margin case.

The invention discloses a gradient descent calculation method for protecting privacy data. The method is used in gradient function computation of machine learning including one or more data providers,a decryption service provider, and a computing resource provider,. The method is suitable for carrying out fitting calculation on a sigmoid function by utilizing a polynomial function similar to thesigmoid function contour or carrying out fitting calculation on the sigmoid function by utilizing a piecewise function similar to the sigmoid function contour. The method comprises the steps of homomorphic encryption key generation and distribution, training parameter negotiation, data encryption and summarization and gradient descent. The method is high in precision, and precision loss caused bydata processing in the calculation process is within a controllable range; the security is high, and the input data and the intermediate data can meet the semantic security requirements in the calculation process; flexibility is good, and two or more participants can participate in calculation; and the expansibility is good, and the original gradient descent can be expanded to a Newton method or abatch gradient descent.