240 results about "Random simulation" patented technology

A method, computer program product, and computer system for configuring a stochastic simulation scenario, wherein the stochastic simulation scenario may include one or more variables without a complete probability distribution. The stochastic simulation scenario may be executed to generate one or more results of the stochastic simulation scenario. At least a portion of the one or more variables without the probability distribution may be optimized using one or more optimization metrics on the one or more results of the stochastic simulation scenario.

The present invention discloses a multi-year regulating storage reservoir optimal scheduling method considering runoff uncertainty. The method comprises the following steps of: (1) analyzing historical reservoir runoff data; (2) establishing a runoff random simulation model, and generating a reservoir simulation annual runoff sequence; (3) simulating annual inflow runoff sequence classification and performing intra-annual distribution to obtain a three-year inflow runoff process sequence on a month scale; (4) establishing a multi-year regulating storage reservoir optimal scheduling model that considers multiple water demands; and (5) reducing dimension by using an optimization algorithm and optimizing a resolution model so as to obtain an optimal discharging and water supply decision. According to the method provided by the present invention, the scheduling with maximized comprehensive benefits of long-term multi-target operation can be performed on a multi-year regulating storage reservoir by considering runoff uncertainty, so that the method is suitable for promotion in long-term optimal scheduling of the multi-year regulating storage reservoir in China.

A method, system, and data structure for incorporating random instrumentation logic within a simulation model. The data structure of the present invention includes a first field containing data representing an assigned target and a second field containing data representing a logic value to be assigned to the assigned target. The first field and the second field are incorporated within a comment line of a design target entity source code file. A pre-pended comment identifier field identifies the data structure as a hardware description language comment.

In a finite state machine (FSM_verify) a set of goal states, to be searched for their reachability from a start state, is defined.

An overapproximated path is found from a start state to a goal state by a forward approximation technique. The overapproximated path representation relies upon a partitioning of the state and input bits of FSM_verify. A state matrix of the overapproximated path is organized by time-steps of FSM_verify along a first dimension and by partitions of FSM_verify state bits along a second dimension.

An underapproximated path, along the path of the stepping stone matrix, is determined. Underapproximation is typically accomplished by simulation.

A sequence of states to be output is updated with the underapproximated path.

If a start to goal state sequence has been found, the procedure ends. Otherwise, the above steps of over and under approximation are repeated, using the results of the last underapproximation as a start state.

The invention provides a method for seeking a weak link of an electric network causing voltage sag, which comprises the following steps: recording voltage sag events and electric network faults; calculating a user voltage sag amplitude expected value and the fault probability of each place; establishing a random analog computation model; performing random analog computation to calculating the user voltage sag amplitude expected value; comparing a computing result and a statistic result; changing fault probabilities of different places, and calculating the voltage sag amplitude expected value; and calculating indexes of the weak link of the electric network, comparing the indexes, and obtaining a result. The method starts from identifying a fault place of the electric network which easily causes the voltage sag events, provides calculation of the indexes of the weak link of the electric network, combines two factors of the fault probability of the electric network and a user voltage sag amplitude caused by the fault, and accurately identifies the fault place of the electric network which easily causes large voltage sag amplitude of the electric network so as to provide priority selection basis for planning and establishment, daily maintenance and technical reformation of the electric network.

A circuit for generating chaotic signals implemented using heterojunction bipolar transistors (HBTs) and utilized in low probability intercept communications. The HBT chaotic circuit generates truly random analog signals in the GHz range that are non-repeating and deterministic and may not be replicated by preloading a predetermined sequence. A fully differential autonomous chaotic circuit outputs two pairs of chaotic signals to be used in a communication system. As it is impossible to generate identical chaotic signals at the transmitter and receiver sites, the receiver itself sends the chaotic signal to be used for encoding to the transmitter. The receiver includes a chaotic signal generator and digitizes, upconverts, and transmits the generated chaotic signal to the transmitter. The transmitter uses the received chaotic signal to code data to be transmitted. The receiver decodes the transmitted data that is encoded by the chaotic signal to retrieve the transmitted data.

The invention relates to a test method for simulating long-term deformation of a rockfill. The test method comprises the following steps of: (1) building a strength degradation model according to a rockfill isochronous stress-strain curve acquired by an indoor triaxial test; (2) randomly simulating a three-dimensional rockfill particle set; and (3) calculating and drawing a long-term deformation curve for rockfill particle flowing deformation by utilizing a rockfill particle random model and the strength degradation model. The test method disclosed by the invention has the advantages that the simulation test method can observe slippage, rotating and cracking of a particle in a flowing deformation simulation process in real time, each fabric quantity is conveniently extracted, the long-term deformation curve of the rockfill is drawn according to test data, non-linear stress-strain parameters can be more accurately solved, basis is provided for numerical calculation of a rockfill dam, and certain reference base and theoretical guidance can be provided for researching problems, such as the long-term deformation, of some rockfill dam projects.

The invention relates to a meteorological-energy-contained integrated energy system typical scene set generation method, and belongs to the technical field of electric power system operation and analysis. The meteorological-energy-contained integrated energy system typical scene set generation method is characterized in that modeling is performed on the meteorological correlation based on a Copula function theory and a Latin hypercube sampling theory; the correlation between meteorological variables is fully considered; the algorithm can significantly improve accuracy of random production simulation of the meteorological variables; and an optimal quantile theory based on Wasserstein distance is used to perform discretization on randomly simulated continuous variables to obtain a small number of integrated energy system typical scene sets. In the meteorological-energy-contained integrated energy system typical scene set generation method, the optimal quantile theory can generate extreme scenes and can greatly improve the calculating precision. The optimal quantile theory utilizes the discrete variables to enable the meteorological-energy-contained integrated energy system typical scene set generation method to be distinguished from other existing research results. The generated typical scene sets can help an operator to analyze the problem brought to operation and planning of the integrated energy system by nondeterminacy, and the analysis result of typical scenes can provide support for safe and stable running of the system.

The invention relates to an active distribution network fault recovery method with consideration of random variation of distributed power supply outputs. The method is characterized by comprising thefollowing steps: step one, carrying out active distribution network island division based on a depth and breadth alternate joint strategy; and step two, on the basis of comprehensive consideration offault recovery whole-period flow changes, carrying out active distribution network reconstruction optimization by using a low-offset stochastic simulation method. Therefore, the maximum output of theDG is utilized fully and loads are recovered as many as possible; and uninterrupted power supply of important loads is ensured.

One embodiment of the present invention provides a system which verifies a circuit design by biasing input stimuli for the circuit design to satisfy one or more temporal coverage properties to be verified for the circuit design. This system performs a simulation in which random input stimuli are applied to the circuit design. The system performs the simulation by using a finite state automaton (FSA) instance for a temporal coverage property to observe inputs and outputs of the circuit, and by using soft constraints associated with the FSA instance to bias the input stimuli for the circuit design so that the simulation is likely to progress through a sequence of states which satisfy the temporal coverage property.

The invention provides a probabilistic earthquake economic loss calculation method and system. The method comprises the following steps: selecting a seismic zone and a potential seismic source regioninfluencing a target region, and determining a seismic activity model and seismic activity parameters; generating a seismic event database through a Monte Carlo random simulation method; selecting anattenuation model, and calculating the seismic intensity of any field point in the target area according to the seismic directory library; calculating the economic loss of the target area according tothe seismic intensity and the macroeconomic vulnerability model; and calculating the earthquake loss occurrence probability of any field point in t years and the economic loss of the field point under the specified probability condition in combination with a large number theorem and a full probability formula. The system comprises a model and parameter determination unit, an earthquake event database generation unit, an earthquake intensity calculation unit, an economic loss calculation unit and an earthquake loss occurrence probability and loss calculation unit. The method considers that thefield points may suffer from the same intensity influence for many times, and provides technical support for earthquake loss prediction.

The present invention relates to a new random generation method of rainfall events. The method comprises the following steps: (1) segmenting rainfall events according to the definition of rainfall events, and extracting rainfall characteristics and rainfall course lines of the rainfall events; (2) randomly simulating rainfall eigenvalues based on the Copula method; (3) based on the K-Means clustering analysis method, classifying the rainfall course lines, and introducing the clustering effective discriminant method to optimize the optimal classification number of rainfall patterns; (4) according to the appearance probability of the rainfall patterns, using the converted Monte Carlo method to randomly generate the rainfall patterns; and (5) using the multi-step combination method to combine the randomly simulated rainfall eigenvalues and the rainfall patterns to reconstruct the rainfall events. According to the method provided by the present invention, the dependency between the rainfall capacity and the rainfall duration are taken into account, so that the simulation is more in line with the actual situation and the simulation precision is improved; different rainfall patterns are taken into account, so that the technical support is provided for the government to take different response tactics for water allocation and storage; and the sequence length of the rainfall events can be significantly increased.