Hybrid state-space time integration of rotating beams

In this paper, we develop a formalism based on either spatially or temporally integrated electromagnetic (EM) Lagrangian, which provides new insights about the near-field reactive energy around generic antennas for arbitrary spatio-temporal excitation signals. Using electric and magnetic fields calculated via FDTD technique and interpolation routines, we compute and plot the normalized values of space/time integrated EM Lagrangian around antennas. While the time-integration of EM Lagrangian sheds light onto the spatial distribution of inductive/capacitive reactive energy, time-variation of spatially integrated EM Lagrangian can help in design of ultra-wideband (UWB) MIMO antennas with low mutual coupling. The EM Lagrangian approach can assist in design of energy harvesting and wireless power transfer systems, as well as for electromagnetic interference mitigation applications.

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Lp-valued stochastic convolution integral driven by Volterra noise

Stochastics and Dynamics ◽

10.1142/s021949371850048x ◽

2018 ◽

Vol 18 (06) ◽

pp. 1850048 ◽

Cited By ~ 7

Author(s):

Petr Čoupek ◽

Bohdan Maslowski ◽

Martin Ondreját

Keyword(s):

Banach Space ◽

State Space ◽

Stochastic Partial Differential Equations ◽

Main Tool ◽

Space Time ◽

Convolution Integral ◽

Hölder Continuous ◽

Stochastic Convolution ◽

Wiener Chaos ◽

Convolution Integrals

Space-time regularity of linear stochastic partial differential equations is studied. The solution is defined in the mild sense in the state space [Formula: see text]. The corresponding regularity is obtained by showing that the stochastic convolution integrals are Hölder continuous in a suitable function space. In particular cases, this allows us to show space-time Hölder continuity of the solution. The main tool used is a hypercontractivity result on Banach-space valued random variables in a finite Wiener chaos.

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The Improved 4-PSK 4-State Space-Time Trellis Code with Two Transmit Antennas

Communication and Networking - Communications in Computer and Information Science ◽

10.1007/978-3-642-17604-3_34 ◽

2010 ◽

pp. 284-290

Author(s):

Ik Soo Jin

Keyword(s):

State Space ◽

Space Time ◽

Trellis Code ◽

Space Time Trellis Code

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A Space-Time Parallel Method to Solve Space-Dependent Neutron Kinetics Equations in Hexagonal-Z Geometry

Volume 3: Nuclear Fuel and Material, Reactor Physics, and Transport Theory ◽

10.1115/icone26-81213 ◽

2018 ◽

Author(s):

Zhizhu Zhang ◽

Yun Cai ◽

Xingjie Peng ◽

Qing Li

Keyword(s):

Nuclear Reactor ◽

Time Integration ◽

Euler Method ◽

Space Time ◽

Parallel Method ◽

Sequential Method ◽

Neutron Kinetics ◽

Nodal Method ◽

Backward Euler ◽

Parareal Method

Neutron kinetics plays an important role in reactor safety and analysis. The backward Euler method is the most widely used time integration method in the calculation of space-dependent nuclear reactor kinetics. Diagonally Implicit Runge-Kutta (DIRK) method owns high accuracy and excellent stability and it could be applied to the neutron kinetics for hexagonal-z geometry application. As solving the neutron kinetics equations is very time-consuming and the number of available cores continues to increase with parallel architectures evolving, parallel algorithms need to be designed to utilize the available resources effectively. However, it is difficult to parallel in time axis since the later moment is strongly dependent on the previous moment. In this paper, the Parareal method which is a time parallel method and implemented by MPI in the processor level is studied in the hexagonal-z geometry with the help of DIRK method. In order to make good use of the parallelism, a parallel strategy in the space direction is also used. In the coarse nodal method, many same operations are finished in the nodes and these operations could be parallel by OpenMP in the thread level since they are independent. Several transient cases are used to validate this method. The results show that the Parareal method gets a fast-convergent speed such as only 2∼3 iterations are needed to convergent. This space-time parallel method could reduce the cost time compared to the sequential method.

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