TOPOLOGY DEPENDENCE IN LATTICE SIMULATIONS OF NON-LINEAR PDES ON A MIMD COMPUTER

We tested the parallelization of explicit schemes for the solution of non-linear classical field theories of complex scalar fields which are capable of simulating hadronic collisions. Our attention focused on collisions in a fractional model with a particularly rich inelastic spectrum of final states. Relativistic collisions of all types were performed by computer on large lattices (64 to 256 sites per dimension). The stability and accuracy of the objects were tested by the use of two other methods of solutions: Pseudo-spectral and semi-implicit. Parallelization of the Fortran code on a 64-transputer MIMD Volvox machine revealed, for certain topologies, communication deadlock and less-than-optimum routing strategies when the number of transputers used was less than the maximum. The observed speedup, for N transputers in an appropriate topology, is shown to scale approximately as N, but the overall gain in execution speed, for physically interesting problems, is a modest 2–3 when compared to state-of-the-art workstations.

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A Class of Explicit Integrators with o-grid Interpolation for Solving Non-linear Systems of First Order ODEs

Journal of Advances in Mathematics and Computer Science ◽

10.9734/jamcs/2020/v35i330263 ◽

2020 ◽

pp. 106-118

Author(s):

U. W. Sirisena ◽

S. I. Luka ◽

S. Y. Yakubu

Keyword(s):

Research Work ◽

Stability And Convergence ◽

Initial Value ◽

First Order ◽

Non Linear ◽

Improved Stability ◽

Linear Problems ◽

The Stability ◽

Stability And Accuracy ◽

Grid Interpolation

This research work is aimed at constructing a class of explicit integrators with improved stability and accuracy by incorporating an off-gird interpolation point for the purpose of making them effcient for solving stiff initial value problems. Accordingly, continuous formulations of a class of hybrid explicit integrators are derived using multi-step collocation method through matrix inversion technique, for step numbers k = 2; 3; 4: The discrete schemes were deduced from their respective continuous formulations. The stability and convergence analysis were carried out and shown to be A(α)-stable and convergent respectively. The discrete schemes when implemented as block integrators to solve some non-linear problems, it was observed that the results obtained compete favorably with the MATLAB ode23 solver.

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Investigation of the stability of periodic motions in a nonlinear automatic control system based on the fast fourier transform

Proceedings of the Mavlyutov Institute of Mechanics ◽

10.21662/uim2003.1.024 ◽

2003 ◽

Vol 3 ◽

pp. 297-307

Author(s):

V.V. Denisov

Keyword(s):

Fourier Transform ◽

Control System ◽

Automatic Control ◽

Fast Fourier Transform ◽

Automatic Control System ◽

Resonance Phenomenon ◽

Periodic Motions ◽

Multiply Connected ◽

Non Linear ◽

The Stability

An approach to the study of the stability of non-linear multiply connected systems of automatic control by means of a fast Fourier transform and the resonance phenomenon is considered.

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Underground Microseismic Event Monitoring and Localization within Sensor Networks

Sensors ◽

10.3390/s21082830 ◽

2021 ◽

Vol 21 (8) ◽

pp. 2830

Author(s):

Sili Wang ◽

Mark P. Panning ◽

Steven D. Vance ◽

Wenzhan Song

Keyword(s):

Sensor Networks ◽

Real Time ◽

Information Needs ◽

Localization Algorithm ◽

Distributed Sensors ◽

Distributed Sensor ◽

Microseismic Events ◽

The Stability ◽

Stability And Accuracy

Locating underground microseismic events is important for monitoring subsurface activity and understanding the planetary subsurface evolution. Due to bandwidth limitations, especially in applications involving planetarily-distributed sensor networks, networks should be designed to perform the localization algorithm in-situ, so that only the source location information needs to be sent out, not the raw data. In this paper, we propose a decentralized Gaussian beam time-reverse imaging (GB-TRI) algorithm that can be incorporated to the distributed sensors to detect and locate underground microseismic events with reduced usage of computational resources and communication bandwidth of the network. After the in-situ distributed computation, the final real-time location result is generated and delivered. We used a real-time simulation platform to test the performance of the system. We also evaluated the stability and accuracy of our proposed GB-TRI localization algorithm using extensive experiments and tests.

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Explicit parallel co-simulation approach: analysis and improved coupling method based on H-infinity synthesis

Multibody System Dynamics ◽

10.1007/s11044-021-09785-x ◽

2021 ◽

Author(s):

Weitao Chen ◽

Shenhai Ran ◽

Canhui Wu ◽

Bengt Jacobson

Keyword(s):

Frequency Domain ◽

Wide Frequency Range ◽

Coupling Method ◽

Sampled Data ◽

H Infinity ◽

First Case ◽

Communication Step ◽

Coupling Variables ◽

The Stability ◽

Stability And Accuracy

AbstractCo-simulation is widely used in the industry for the simulation of multidomain systems. Because the coupling variables cannot be communicated continuously, the co-simulation results can be unstable and inaccurate, especially when an explicit parallel approach is applied. To address this issue, new coupling methods to improve the stability and accuracy have been developed in recent years. However, the assessment of their performance is sometimes not straightforward or is even impossible owing to the case-dependent effect. The selection of the coupling method and its tuning cannot be performed before running the co-simulation, especially with a time-varying system.In this work, the co-simulation system is analyzed in the frequency domain as a sampled-data interconnection. Then a new coupling method based on the H-infinity synthesis is developed. The method intends to reconstruct the coupling variable by adding a compensator and smoother at the interface and to minimize the error from the sample-hold process. A convergence analysis in the frequency domain shows that the coupling error can be reduced in a wide frequency range, which implies good robustness. The new method is verified using two co-simulation cases. The first case is a dual mass–spring–damper system with random parameters and the second case is a co-simulation of a multibody dynamic (MBD) vehicle model and an electric power-assisted steering (EPAS) system model. Experimental results show that the method can improve the stability and accuracy, which enables a larger communication step to speed up the explicit parallel co-simulation.

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A Digital Framework to Predict the Sunshine Requirements of Landscape Plants

Applied Sciences ◽

10.3390/app11052098 ◽

2021 ◽

Vol 11 (5) ◽

pp. 2098

Author(s):

Heyi Wei ◽

Wenhua Jiang ◽

Xuejun Liu ◽

Bo Huang

Keyword(s):

Solar Radiation ◽

Plant Species ◽

Large Scale ◽

Normal Growth ◽

Adaptive Selection ◽

Landscape Plant ◽

Landscape Plants ◽

The Stability ◽

Stability And Accuracy ◽

The City

Knowledge of the sunshine requirements of landscape plants is important information for the adaptive selection and configuration of plants for urban greening, and is also a basic attribute of plant databases. In the existing studies, the light compensation point (LCP) and light saturation point (LSP) have been commonly used to indicate the shade tolerance for a specific plant; however, these values are difficult to adopt in practice because the landscape architect does not always know what range of solar radiation is the best for maintaining plant health, i.e., normal growth and reproduction. In this paper, to bridge the gap, we present a novel digital framework to predict the sunshine requirements of landscape plants. First, the research introduces the proposed framework, which is composed of a black-box model, solar radiation simulation, and a health standard system for plants. Then, the data fitting between solar radiation and plant growth response is used to obtain the value of solar radiation at different health levels. Finally, we adopt the LI-6400XT Portable Photosynthetic System (Li-Cor Inc., Lincoln, NE, USA) to verify the stability and accuracy of the digital framework through 15 landscape plant species of a residential area in the city of Wuhan, China, and also compared and analyzed the results of other researchers on the same plant species. The results show that the digital framework can robustly obtain the values of the healthy, sub-healthy, and unhealthy levels for the 15 landscape plant species. The purpose of this study is to provide an efficient forecasting tool for large-scale surveys of plant sunshine requirements. The proposed framework will be beneficial for the adaptive selection and configuration of urban plants and will facilitate the construction of landscape plant databases in future studies.

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