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Simulation models have proved to be useful for examining the performance of different system configurations and/or alternative operating procedures for complex logistic or manufacturing systems. However, when applying simulation techniques to increase the performance of those systems, several limitations arise due to their inability to evaluate more than a fraction of the immense range of options available. Simulation-optimization is one of the most popular approaches to improve the use of simulation models as a tool to obtain the best (optimal or quasi-optimal) decision variable values that minimize a certain objective function. However, despite the success of several simulation-optimization packages, many technical barriers still remain. The authors describe a new approach to integrate evaluation (simulation) methods with search methods (optimization) based on not only simulation results but also information from the simulation model.

Integrated Acceptance and Sustainability Assessment Model (IASAM) is a new approach for evaluation of technologies that combines socio-economic aspects and socio-technical characteristics of technology development and exploitation. Previous IASAM model was based on UTAUT acceptance model and it was laborious. The potential acceptance is a very challenging issue and has been studied by many authors. One of the leading theories regarding the acceptance recognition is Theory on Diffusion of Innovations by Rogers. This paper describes the application of this theory in evaluation of technology acceptance and sustainability within the IASAM2 model.

Abstract:The Traffic Alert and Collision Avoidance System (TCAS) is a world-wide accepted lastresort means of reducing the probability and frequency of mid-air collisions between aircraft. Unfortunately, it is widely known that in congested airspace, the use of the TCAS may actually lead to induced collisions. Therefore, further research regarding TCAS logic is required. In this paper, an encounter model is formalised to identify all of the potential collision scenarios that can be induced by a resolution advisory that was generated previously by the TCAS without considering the downstream consequences in the surrounding traffic. The existing encounter models focus on checking and validating the potential collisions between trajectories of a specific scenario. In contrast, the innovative approach described in this paper concentrates on quantitative analysis of the different induced collision scenarios that could be reached for a given initial trajectory and a rough specification of the surrounding traffic. This approach provides valuable information at the operational level. Furthermore, the proposed encounter model can be used as a test-bed to evaluate future TCAS logic changes to mitigate potential induced collisions in hot spot volumes. In addition, the encounter model is described by means of the coloured Petri net (CPN) formalism. The resulting state space provides a deep understanding of the cause-and-effect relationship that each TCAS action proposed to avoid an actual collision with a potential new collision in the surrounding traffic. Quantitative simulation results are conducted to validate the proposed encounter model, and the resulting collision scenarios are summarised as valuable information for future air traffic management (ATM) systems.

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