264 results about "Transient analysis" patented technology

The invention discloses an intersection traffic flow characteristic analysis and vehicle moving prediction method based on trajectory data, and belongs to the technical field of intelligent traffic system and traffic flow parameter acquisition. The method starts with space transient analysis of a vehicle original trajectory, and describes and analyzes trajectory local geometrical characteristics at different angles, forms a multilevel spectral clustering processing framework based on a vehicle original rough movement track, and automatically extracts and analyzes a plurality of traffic direction modes of an intersection included in the trajectory data. With the basis, the method can acquire intersection sub-phase (signal control intersection) traffic flow and travel time of vehicles in all directions passing through the intersection, and other detailed traffic characteristic parameters, as important complement of conventional traffic data. Through tracking travelling tracks of all moving vehicles at present moment, a traffic direction trajectory mode matching method is used to predict the next behavior of the vehicles, thereby being beneficial for warning safety risks which may exist on an intersection in real time.

Methods and apparatuses for transient analyses of a circuit using a hierarchical approach. In one embodiment, the cells are grouped locally on the power supply network according to average power dissipation. A time varying current of each cell group is estimated using a probabilistic approach to represent the cell group so that the probability of a more severe waveform for the current of the cell group is under a certain level. For example, the cells in a group are partitioned as switching cells and non-switching cells using cell toggle rates for the determination of the time varying current. The circuit model of the power supply network includes the current sources according to the estimated time varying currents for the cell groups, the power supply wire resistance, the power supply to ground wire capacitance, well capacitance and the de-coupling capacitance from non-switching cells.

The method belongs to the routing design area in VLSI physical design. The characters of the method of using computers to solve the set of linear equations are as follows. Based on the features of that the power wire / ground, wire network of the application specific integrated circuit (ASIC) contains a great lot of the chain topology, the parameters R, L, C and the current source in the RLC circuit are equivalent to the nodes at the two ends of the chain. The set of linear equations is listed for the equivalent circuits composed of the nodes at the two ends of all chains. Then, the magnitudes of voltage of the mergered nodes in all chains are determined. The method has the advantages of fast and saving the memory. The scale of the chips to be treated is posible to be enlarged and the precision meets the demand.

The specification discloses a downhole tool that determines hydraulic permeability of a downhole formation taking into account one or both of the dip angle of the borehole relative to the formation, and damage to the borehole wall and invasion of borehole fluid—collectively referred to as skin.

The invention provides a numerical simulation analysis method for a loudspeaker falling process. The method comprises the steps of firstly building a finite element simulation model: 1) building a falling simulation geometric model containing a loudspeaker individual and concrete poured bricks; 2) setting a material model, a contact boundary condition, an initial condition, a constraint condition and a load force in a solid mechanics physical field; 3) setting material parameters; and 4) setting grid type and size, and performing grid division to generate the finite element model; and secondly solving the finite element model by adopting a transient analysis method, and performing post-processing to obtain change relationships of energy, stress, strain and displacement in the loudspeaker falling process, wherein the change relationships specifically include 1) the change relationship of total kinetic energy and total elastic strain energy of the loudspeaker along with time, 2) a distribution diagram of stress on a loudspeaker structure at a specified moment, 3) a displacement of a mass point on the loudspeaker structure at the specified moment, and 4) plastic strain capacity and distribution diagram of the loudspeaker.

The invention discloses a synchronous phasor measuring device of a ship electrical power system; the synchronous phasor measuring device comprises a processor, an analog-to-digital conversion module, a IIC extension switching value input module, a IIC extension switching value output module, a local area network controller module, a pulse width modulation module, a first asynchronous serial interface UART (Universal Asynchronous Receiver / Transmitter) module and a second asynchronous serial interface UART module and an Ethernet control module; the voltage and the magnitude-of-current of a measuring point of the ship electrical power system or the switching value of a relay or breaker of the electric power system are calculated and logically judged through the processor, then are respectively output through the IIC extension switching value output module and the pulse width modulation (PWM) module and finally are transmitted through the first asynchronous serial interface UART module, the second asynchronous serial interface UART module, the local area network controller module and / or the Ethernet control module. The synchronous phasor measuring device has the functions of dynamic measurement and transient measurement on the electric power system, can be used for carrying out transient analysis and dynamic monitoring on the ship electrical power system and simultaneously has the functions of onsite UART debugging and firmware upgrading of remote equipment by using an Ethernet RJ450 interface.

The present invention relates to a multidimensional modeling method and a simulation method for a modular multilevel converter, comprising steps of: (1) establishing equivalent models of half-bridge submodules and establishing Thevenin equivalent models of submodules according to the Thevenin's Equivalence Theorem; cascading the Thevenin equivalent models of submodules to establish a high-speed equivalent model of a modular multilevel converter; (2) acquiring stray parameters, putting a stray capacitor and a stray resistor at corresponding positions in the high-speed equivalent model established in step (1), to establish a wide frequency model of the modular multilevel converter; and (3) replacing a submodule of each bridge arm of the wide frequency model established in step (2) with a detailed electromagnetic transient model, to establish a multidimensional model of the modular multilevel converter. The present invention can not only greatly improve the efficiency of system simulation and realize device-level electromagnetic transient analysis, but also simulate the effects of stray elements on system operation so as to facilitate efficient and accurate simulation analysis of the modular multilevel converter.

Vascular conditions are detected non-invasively in the human body using a collection of information from small local regions of the vasculature. An array of accelerometers or other sensors are attached to the head or other points of interest of a patient and blood flow sounds are recorded. Vibration signatures of vessel structures such as branches, aneurysms, stenosis, etc. using random, periodic, band limited or transient analysis provides a library for further processing. The signature library is used to localize the origin of the recognized vascular feature, and the localized feature is presented to the physician in a clinically relevant manner.