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Markov Processes
Published in Michael W. Carter, Camille C. Price, Ghaith Rabadi, Operations Research, 2018
Michael W. Carter, Camille C. Price, Ghaith Rabadi
O-MATRIX is a matrix-based scripting language which originated as an object-oriented analysis and visualization tool for Windows computing environments. Data and procedures are built with a text editor, and computations are expressed via a powerful, but small and easy-to-learn, language in which all operations are performed on matrix objects. This integrated technical computing environment is now aimed at providing high performance capabilities for solving computationally intensive mathematical and engineering problems. O-MATRIX is compatible with a version of MATLAB from MathWorks. See the software’s website and user manual for a more detailed description of O-MATRIX.
Digital twin application with horizontal coordination for reinforcement-learning-based production control in a re-entrant job shop
Published in International Journal of Production Research, 2022
Kyu Tae Park, Seung-Woo Jeon, Sang Do Noh
Subsequently, the policy network construction module derives the I/O matrix from . The input of is the state , and the output is the action . The reward is used when is learning. The duelling networks technique is used to learn the advantage function and value function and return the parameters. The duelling networks are constructed as a single network rather than separate values and policy networks. Accordingly, the existing method using has the advantage of fewer additional reflection functions. In addition, the logs and indicators related to DT simulation are easy to collect. This approach is appropriate for horizontal coordination with a DT because the combined weights can be learned at every step regardless of the action. Moreover, the learning process can be completed with fewer episodes compared with that in DQN, resulting in better performance as the number of action types increases.
A review of revaporisation behaviour of radioactive Cs deposits and its impact on the source term in severe nuclear accidents from Phébus FP results and single effect testing
Published in Journal of Nuclear Science and Technology, 2019
Kevin Knebel, Jorma Jokiniemi, Paul David Bottomley
However, the matrix is degrading with time, due to the weathering and the accumulation of irradiation damage. Thus, decreased hardness and increased fracturing were observed with time and the flaking off of particles from the lava in certain locations. Other lavas showed relatively little change with time. There is also Chernobyl corium derived from UO2-cladding interactions. In addition, there are the hot particles (100–1 µm size) that were all from degraded UO2 and cladding sometimes along with structural materials (Fe, Ni). These are highly radioactive and contain various fission products (such as Cs-137) mainly in a U-Zr-O matrix. However, the contents of fission products, such as Cs-137 or Sb-125 varied from location to location, suggesting that the exact composition varied with the conditions of the hot particle formation and release. These are found both inside the reactor and in the surrounding area [54]. The formation of the hot particles appears to be due to slow oxidation in air of the larger fuel fragments and may be particularly susceptible if they were not fully oxidised when released.
Synthesis of boron suboxide (B6O) with alkaline earth metal oxide materials with improved properties
Published in Particulate Science and Technology, 2019
E. N. Ogunmuyiwa, O. T. Johnson, I. Sigalas
Figure 7(a–c) shows the SEM images of the crack propagation on the polished surfaces of hot-pressed B6O-alkaline earth oxide materials. Crack propagations on these materials could predominantly be related to a transgranular mode and occasions of crack deflection with low deflection angles on the secondary phase (e.g., Figure 7(c)). Most of the crack deflections were either caused by the presence of the secondary phase and/or by the inherent pores. These deflections were reportedly caused by non-wetted grain boundary (Kleebe et al. 2008; Herrmann et al. 2009b). Some similar findings were also observed by other authors (Herrmann et al. 2013; Thiele, Herrmann, and Michaelis 2013). In comparison to the pure B6O, the crack path lengths of the B6O-alkaline earth oxide materials are shorter. The deflection observed can be explained by the stresses that exist in the material. The B6O matrix has a different thermal expansion coefficient (CTE) compared to the secondary phase(s). This could result in the formation of large internal stress when the material is cooled from the sintering temperature. This difference can induce a tangential compressive stress near the particle/matrix interface and thereby diverts the crack around the particle, making the material tough.