Motivated by applications in health care systems, this study focused on queueing network models with instances of simultaneous resource possession under capacity restrictions in different stages. Customers during service at certain nodes in the first-level or primary system may simultaneously need service from a second-level server. In this…

Artificial intelligence (AI) aims to build intelligent systems that can interact with and assist humans. During the interaction, a system learns the requirements from the human user and adapts to the needs to complete tasks. A popular type of interactive system is retrieval-based, where the system uses a retrieval function to retrieve relevant…

Massive open online courses provide virtually unlimited numbers of learners with access to instructors and course materials from high-status institutions. These courses are technologically intensive in ways that traditional online courses are not, which invites an examination of how the work to create these new forms may or may not work within…