A Discrete Particle Simulation Study of Solids Mixing in a Pressurized Fluidized Bed

A fluidized bed containing polymeric particles is investigated using a state-of-the-art soft-sphere discrete particle model (DPM). The pressure dependency of particle mixing, flow patterns and bubble behaviour are analysed. It is found that with increasing pressure a less distinct bubble-emulsion structure and improved solids mixing can be observed

Robot Navigation in Unseen Spaces using an Abstract Map

Human navigation in built environments depends on symbolic spatial information which has unrealised potential to enhance robot navigation capabilities. Information sources such as labels, signs, maps, planners, spoken directions, and navigational gestures communicate a wealth of spatial information to the navigators of built environments; a wealth of information that robots typically ignore. We present a robot navigation system that uses the same symbolic spatial information employed by humans to purposefully navigate in unseen built environments with a level of performance comparable to humans. The navigation system uses a novel data structure called the abstract map to imagine malleable spatial models for unseen spaces from spatial symbols. Sensorimotor perceptions from a robot are then employed to provide purposeful navigation to symbolic goal locations in the unseen environment. We show how a dynamic system can be used to create malleable spatial models for the abstract map, and provide an open source implementation to encourage future work in the area of symbolic navigation. Symbolic navigation performance of humans and a robot is evaluated in a real-world built environment. The paper concludes with a qualitative analysis of human navigation strategies, providing further insights into how the symbolic navigation capabilities of robots in unseen built environments can be improved in the future.Comment: 15 pages, published in IEEE Transactions on Cognitive and Developmental Systems (http://doi.org/10.1109/TCDS.2020.2993855), see https://btalb.github.io/abstract_map/ for access to softwar

A critical review of the exit-voice-loyalty-neglect literature:limitations, key challenges and directions for future research

The study of human behaviour holds a prominent role in organizational behavior literature. For almost 45 years, the exit, voice, loyalty and neglect typology has attracted scholars’ interest and has been linked to employee responses towards dissatisfaction and problematic events in the workplace. This paper reviews the literature and identifies and addresses key theoretical and methodological deficiencies that the exit, voice, loyalty and neglect typology faces that have been either ignored or undeveloped. Moreover, by unpicking this typology as currently portrayed in the existing literature, it proposes key challenges that need to be addressed and provides directions for future research