Patents
Literature
Hiro is an intelligent assistant for R&D personnel, combined with Patent DNA, to facilitate innovative research.
Hiro

82 results about "Slack variable" patented technology

In an optimization problem, a slack variable is a variable that is added to an inequality constraint to transform it into an equality. Introducing a slack variable replaces an inequality constraint with an equality constraint and a non-negativity constraint on the slack variable.

Modeling and optimized dispatching method of electrical series-parallel system on the basis of energy center

The invention discloses a modeling and optimized dispatching method of an electrical series-parallel system on the basis of an energy center. The modeling and optimized dispatching method comprises the following steps: firstly, establishing an electrical network, a natural gas network and an energy hub model, and coupling the electrical network with the natural gas network through an energy hub to form the electrical series-parallel system; then, taking total energy cost as a target function, and considering various constraint conditions to establish an optimized dispatching mathematic model of the electrical series-parallel system; and carrying out solving by a primal-dual interior-point method, importing a slack variable and a barrier parameter in sequence in a solving process so as to change the model into a model which only contains an equality constraint, then, importing a Lagrange multiplier to obtain a Lagrange function, and solving a non-linear equation set formed by a KKT (Karush-Kuhn-Tucker) condition of the Lagrange function by a Newton method. A constructed example simulation result indicates that an optimization effect on the electrical series-parallel system by the modeling and optimized dispatching method is superior to an independent optimization effect.
Owner:HOHAI UNIV

Improved method for improving stability property of communication system

InactiveCN102710363AReliable and confidential optimal transmission power valueGuaranteed stabilityError preventionSecret communicationCommunications systemSlack variable
The invention discloses an improved method for improving the stability property of a communication system, belonging to the technical field of communication. The improved method comprises the steps of: determining a parameter, a determining an optimization program, simplifying the optimization problem, introducing a slack variable, transforming a half-infinite limit condition into a linear matrix inequality, obtaining a final form of the optimization problem, proving that the solution is an optimal solution, solving an optimal sending power popt, and outputting the optimal sending power popt. According to the improved method, on the premise of considering that the channel state information of a wiretap channel is not completely known, an optimal scheme is re-designed, therefore, the stability property of secret communication is improved. Under the condition of realizing that the state information of the wiretap channel is not completely known, a manual noise covariance matrix and a transmission beam forming vector are combined for optimization design, thus the stability of the secret communication is improved. Compared with the condition of known channel state information, the improved method has remarkable advantages on the stability of the whole system.
Owner:SHANDONG UNIV

Multi-antenna full-duplex system distributed beam forming method based on ADMM (Alternating Direction Method of Multipliers)

The invention discloses a multi-antenna full-duplex system distributed beam forming method based on an ADMM (Alternating Direction Method of Multipliers). The method is applicable to multi-interference combined inhibition of a multi-relay multi-antenna full-duplex system, and reduces total sending power of the system under the constraint of a user rate. By utilizing an ADMM algorithm, the problemthat due to non strict convex of an original problem, convergence cannot be carried out is solved, and meanwhile, a convergence rate is promoted. The method comprises the following steps of: (1) initializing system variables; (2) constructing an ADMM problem in a compact form, and decoupling the problem; and (3) solving an augmented Lagrangian function minimization problem at each relay to obtainoriginal and slack variables, and broadcasting the original and slack variables to all the relays so as to update a dual variable. The step (3) is repeated until a preset stopping criterion is met. Asolution obtained after final iteration is output, and a final iteration solution of the original variable is subjected to feature value decomposition or Gaussian randomization so as to obtain a distributed beam forming matrix and a beam forming vector.
Owner:RESEARCH INSTITUTE OF TSINGHUA UNIVERSITY IN SHENZHEN +1

Convex optimization solving method for optimal power flow of electric power system

The invention relates to a convex optimization solving method for optimal power flow of an electric power system, and belongs to the running and control technology field for an electric power system.According to the method, a non-convex constraint in an optimal power flow problem is converted into a form of subtraction of convex functions, and a non-convex optimal power flow problem is convertedinto a convex optimization problem to obtain a solution through linearization of the convex functions in the non-convex constraint and introduction of slack variables. The method includes the following steps: establishing an optimal power flow optimization model of an electric power system; converting a non-convex power flow equation into a form of subtraction of convex functions; carrying out equivalent conversion of the optimal power flow optimization model of the electric power system; and carrying out convex optimization iterative solving of the optimal power flow optimization model of theelectric power system. The non-convex constraint in the power flow equation of the electric power system is converted into a form of subtraction of the convex functions to enable the non-convex optimal power flow problem to be converted into iterative solving of the convex optimization problem, so highly efficient solving of the optimal power flow problem of the electric power system is realized.
Owner:TSINGHUA UNIV

Interval prediction control modeling and optimizing method based on soft constraints

InactiveCN103995466AAccurate solutionQuick solveAdaptive controlPositive definitenessSlack variable
Provided is an interval prediction control modeling and optimizing method based on soft constraints. The control method comprises the following steps: (1) a quadratic performance index including a constraint item, a control item and an economic item is established based on a process prediction model; (2) whether an overall optimization method is feasible is judged by solving a slack variable; (3) a method for solving a soft constraint slack variable when a control model output constraint is not feasible is provided, and adjustment of the range of a feasible region when an interval prediction control model output constraint is not feasible is realized; and (4) a boundary feasible sequence quadratic programming method is adopted to solve the problem that poor initial point selection causes calculation amount increase of the method or difficulty in finding an optimal solution, the problem that the positive definiteness of a Hessian matrix is destroyed due to the influence of round-off error in calculation, and the like, and to figure out the optimal control input. A complicated multivariable system control model can be established, the control law can be solved accurately and quickly based on soft constraint adjustment, and good control on a multivariable system can be achieved.
Owner:YANSHAN UNIV

Physical layer secure transmission method in OFDM (orthogonal frequency division multiplexing) amplify-and-forward relay system

The invention discloses a physical layer secure transmission method in an OFDM (orthogonal frequency division multiplexing) amplify-and-forward relay system. According to the invention, an amplify-and-forward protocol is adopted in relaying, equivalent channels of all links between a source node and a destination node are estimated at first, and then artificial noises are designed into a null space of a physical channel of a source node-relay-destination node link, so that the artificial noises impose no interference on the destination node. The security rate is maximized under a condition that the source node and a relay node are restricted in power. The optimization problem is non-convex, so slack variable substitution and an ICA technology are adopted to convert the original non-convex problem into a series of nearly convex problems, and thus the problems can be solved by using a CVX tool. A simulation result shows that, the method disclosed by the invention can acquire a good security rate and stable performance. Compared with a destination node cooperative interference method and a noise-free method, the method disclosed by the invention not only can acquire stable and effective security, but also can avoid influences brought about by the position of an eavesdropping node.
Owner:XI AN JIAOTONG UNIV

Convex optimization-based high-precision positioning method

The present invention relates to a convex optimization-based high-precision positioning method in an underwater target positioning problem. The method of the present invention comprises a step of setting the to-be-calculated coordinate of a target as x=[x0,y0,z0]<T>, wherein the step comprises firstly measuring the distances ri between the target to several surrounding beacons and the coordinates ai=[xi, yi, zi]<T> corresponding to the beacons, setting the range finding errors to each beacon as Epsilon i which follow the Gaussian distribution of which the expected value is 0 and the variance is sigma i<2>, and obtaining a range finding equation of the target, etc. By carrying out the formal transformation and adding the limitation conditions on a least-square structure of an underwater target spherical intersecting positioning equation, the least-square structure is transformed into a DC structural form in a convex optimization theory, and further a convex-concave process (CCP) method can be utilized to solve, and aiming at the disadvantage that a direct CCP algorithm need to iterate an initial value in a feasible domain, a slack variable and a penalty function are added in an original optimization equation, thereby expanding the feasible domain, and broadening the limitation to the initial value. Compared with a linear least-square positioning calculation method, the convex optimization-based high-precision positioning method enables the positioning precision to be improved, and realizes the high-precision underwater target positioning.
Owner:HARBIN ENG UNIV

Satellite formation reconstruction algorithm based on random model predictive control

The invention discloses a satellite formation reconstruction algorithm based on stochastic model predictive control, and the algorithm mainly comprises the steps of converting a multi-satellite formation reconstruction problem into a single reference satellite-single surround satellite problem based on two-body hypothesis; determining an initial state and a target state by determining an initial configuration and a target configuration; reconstructing the formation model by using a model prediction control algorithm with disturbance feedback; and performing convex optimization reconstruction on the problem by using a distributed random model predictive control theory. According to the algorithm, the original problem can be converted into a computable convex optimization problem under the condition that only the external perturbation mean value and variance are known, and the system stability is ensured; a system can be allowed to balance between constraint and system performance within a certain range, so that the conservative property of a control system is greatly reduced, and the feasibility and stability of the algorithm are ensured. According to the present invention, the constraint is processed by using a slack variable and a precise penalty function method, so that the iteration feasibility of the algorithm is ensured.
Owner:SICHUAN UNIV

Array antenna beam forming optimization method under non-convex multiple constraints

The invention discloses an array antenna beam forming optimization method under non-convex multiple constraints. The method comprises the following steps: establishing a receiving signal far-field model for an array antenna beam forming problem; taking the side lobe level of the region of interest as a target function, considering main lobe interval shape control and output noise power requirements, adding main lobe interval level upper and lower bound limits and output noise power constraints, and establishing a non-convex optimization problem; therefore, the expected wave beam shape is obtained on the premise of not increasing the output noise power. According to the method, the non-convex constraint is approximated to be a convex upper bound function through the first-order iterative convex approximation algorithm, so that the non-convex multi-constraint optimization problem is approximated to be a convex optimization problem, and solving is easy; besides, the non-negative slack variable is introduced, so that the convergence speed of the algorithm is high, a self-adaptive change penalty factor is designed, and the parameter adjustment process of human experience is reduced; on the premise that it is guaranteed that the expected main lobe shape of a beam directional diagram is obtained, the obtained side lobe level of the region of interest is lower, and interference signals in the side lobe level direction are restrained.
Owner:UNIV OF ELECTRONICS SCI & TECH OF CHINA

Block diagonalization assisted robust transceiver design method in multi-cell MIMO system

The invention provides a block diagonalization assisted robust transceiver design method in a multi-cell MIMO system. The method comprises the following steps: step 1: setting an operation mode of the multi-cell MIMO system; step 2: defining a signal to interference plus noise ratio (SINR) of a single user or receiver, and calculating the signal to interference plus noise ratio of the k user or receiver; step 3: performing block diagonalization precoding by each transmitter according to a local estimation channel; step 4: calculating a lower bound value of the signal to interference plus noise ratio when the channel has a bounded error; step 5: using the lower bound value of the signal to interference plus noise ratio as the signal to interference plus noise ratio of the worst case, importing a slack variable, and transforming to solve a beam forming vector problem of the transmitters or receivers by using a convex optimization method; and step 6: obtaining a robust beam forming vector by using an alternate optimization method. According to the block diagonalization assisted robust transceiver design method provided by the invention, the robustness for the bounded error is relatively high, and each transmitter only uses the local CSI to perform the block diagonalization precoding, thereby reducing the feedback cost and guaranteeing the minimum SINR performance.
Owner:SHANGHAI JIAO TONG UNIV
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products