A TCAD tool for the simulation of the CVD process based on cellular automata

The development of next-generation VLSI circuits with deep submicron technologies demands fundamental understanding of the wafer surface reaction kinetics. Technology cornputer-aided design (TCAD) is essential for modeling real fabrication processes accurately, and allowing predictive simulation during technology research and development. This paper describes a two-dimensional Chemical Vapor Deposition (CVD) process TCAD system based on cellular automata (CAs). The proposed TCAD system can handle the complicated boundary and initial conditions imposed by defects and provide SEM-like cross sectional views. The simulated profiles obtained are in very good agreement with experimental and simulation results found in the literature. Furthermore, a user-friendly interface that enables easy and effective interaction between the user and the TCAD system has been developed

The effects of supraregional innovation and production collaboration on technology development in a multiregional world: A spatial agent-based model study.

With globalization, firms acquire locally unavailable inputs from and collaborate in innovation with firms in other regions. We contend that, depending on the collaboration distances feasible and spatial layout of regions, a core-periphery structure of regions emerges, in which core regions produce more advanced and complex products. We develop a spatial agent-based model of (supraregional) firm collaboration in production and innovation to study technological progress. We find that when collaboration is possible over greater distances, agents produce more advanced and more complex products. Moreover, we find that, in general, the core-periphery structure indeed emerges. However, for some layouts, the core-periphery structure vanishes almost immediately, while for others first becomes stronger, peaks and then vanishes with an increase in collaboration distance. Moreover, we find that the properties of the technology structure play a prominent mediating role, e.g. the effect of supraregional collaboration on technological progress may be strong for some and relatively weak for other structures

Cellular automaton model of crowd evacuation inspired by slime mould

In all the living organisms, the self-preservation behaviour is almost universal. Even the most simple of living organisms, like slime mould, is typically under intense selective pressure to evolve a response to ensure their evolution and safety in the best possible way. On the other hand, evacuation of a place can be easily characterized as one of the most stressful situations for the individuals taking part on it. Taking inspiration from the slime mould behaviour, we are introducing a computational bio-inspired model crowd evacuation model. Cellular Automata (CA) were selected as a fully parallel advanced computation tool able to mimic the Physarum’s behaviour. In particular, the proposed CA model takes into account while mimicking the Physarum foraging process, the food diffusion, the organism’s growth, the creation of tubes for each organism, the selection of optimum tube for each human in correspondence to the crowd evacuation under study and finally, the movement of all humans at each time step towards near exit. To test the model’s efficiency and robustness, several simulation scenarios were proposed both in virtual and real-life indoor environments (namely, the first floor of office building B of the Department of Electrical and Computer Engineering of Democritus University of Thrace). The proposed model is further evaluated in a purely quantitative way by comparing the simulation results with the corresponding ones from the bibliography taken by real data. The examined fundamental diagrams of velocity–density and flow–density are found in full agreement with many of the already published corresponding results proving the adequacy, the fitness and the resulting dynamics of the model. Finally, several real Physarum experiments were conducted in an archetype of the aforementioned real-life environment proving at last that the proposed model succeeded in reproducing sufficiently the Physarum’s recorded behaviour derived from observation of the aforementioned biological laboratory experiments