In this paper, a new model to parallelize the backward-chaining inference technique in production systems called ParBack is presented. In this model, the data dependencies between rules are analyzed and then converted to special notations that constitute the search space. Parallelism is exploited in three directions: some processors are dedicated to perform the inference process; other processors perform processes that guide the inference process to the useful paths in the search space; and a third group of processors performs the rule-pruning principle that reduces the length of the paths in the search space. The results of the simulation study on ParBack show that around 850 folds of speed-up can be obtained.


A frequency domain nonparametric identification method for nonlinear structures: Describing surface method
Karaagacli, Taylan; Özgüven, Hasan Nevzat (Elsevier BV, 2020-10-01)
In this paper a new method called 'Describing Surface Method' (DSM) is developed for nonparametric identification of a localized nonlinearity in structural dynamics. The method makes use of the Nonlinearity Matrix concept developed in the past by using classical describing function theory, which assumes that nonlinearity depends mainly on the response amplitude and frequency dependence is negligible for almost all of the standard nonlinear elements. However, this may not always be the case for complex nonli...
A new steering law for redundant control moment gyroscope clusters
Tekinalp, Ozan (Elsevier BV, 2005-10-01)
A new inverse kinematics algorithm is developed that may provide singularity avoidance or may be used for quick transition through a singularity with small torque errors. To avoid singularities, angular momentum trajectory of the control moment gyro cluster during the maneuver is to be simulated in advance for the calculation of singularity free gimbal histories. The steering law proposed accurately generates the required torques making it suitable to be used in a feedback system. The desired gimbal traject...
AKGUN, MA (American Institute of Aeronautics and Astronautics (AIAA), 1994-02-01)
A new family of modal methods for the calculation of eigenvector derivatives in non-self-adjoint systems with a singular coefficient matrix is developed. The family contains the modal and modified modal methods as a subset. In the family, the component of the mth eigenvector in the expansion of the derivative of the jth eigenvector is multiplied by various powers of the eigenvalue ratio lambda(i)/lambda(m), thereby accelerating convergence. The family of methods is applied to a self-adjoint example problem,...
A parallel gas-kinetic Bhatnagar-Gross-Krook method for the solution of viscous flows on two-dimensional hybrid grids
Ilgaz, M.; Tuncer, İsmail Hakkı (Informa UK Limited, 2009-01-01)
In this study, a parallel implementation of gas-kinetic Bhatnagar-Gross-Krook method on two-dimensional hybrid grids is presented. Boundary layer regions in wall bounded viscous flows are discretised with quadrilateral grid cells stretched in the direction normal to the solid surface while the rest of the flow domain is discretised by triangular cells. The parallel solution algorithm on hybrid grids is based on the domain decomposition using METIS, a graph partitioning software. The flow solutions obtained ...
Estimation of pico-satellite attitude dynamics and external torques via Unscented Kalman Filter
Söken, Halil Ersin (FapUNIFESP (SciELO), 2014-01-01)
In this study, an Unscented Kalman Filter (UKF) algorithm is designed for estimating the attitude of a picosatellite and the in-orbit external disturbance torques. The estimation vector is formed by the satellite's attitude, angular rates, and the unknown constant components of the external disturbance torques acting on the satellite. The gravity gradient torque, residual magnetic moment, sun radiation pressure and aerodynamic drag are all included in the estimated external disturbance torque vector. The sa...
Citation Formats
S. ABUSUOD and M. TOLUN, “A PARALLEL BACKWARD-CHAINING INFERENCE ENGINE FOR PRODUCTION SYSTEMS,” 1992, vol. 1707, p. 146, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/64891.