Table 3.

Overview of research directions and concepts and their relations to neuromorphic systems integration challenges.

Research directions and concepts	Neuromorphic systems integration challenges and concepts
	Communication	Virtualization	Programming	Testing and validation
Neuromorphic-system proxy	×	×	×	×
Neuromorphic-system simulation		⊗		⊗
Microservices	×	×
Communication and data models	×	×
Semantic technologies	⊗
Embeddings	⊗
Soft state	×	×
PubSub messaging	×
Graph data and querying	×	×	×
Declarative programming			⊗	⊗
Process calculus			⊗
Machine learning			⊗	⊗
Statistical evaluation				⊗

The symbol “⊗” indicates that a concept has been connected to neuromorphic systems in the literature discussed in this article, while “ × ” indicates that the connection is introduced here. All connections indicated in this table are subjects for further research. The relations between these concepts and conventional digital computing are described in Section 3, but are not illustrated here.